CSES - Aalto Competitive Programming 2026 - wk5 - Mon

Submission details
Task:	Freight trains
Sender:	aalto26em_005
Submission time:	2026-09-28 17:45:12 +0300
Language:	Python3 (PyPy3)
Status:	READY
Result:	WRONG ANSWER

Test results
test	verdict	time
#1	ACCEPTED	0.04 s	details
#2	WRONG ANSWER	0.04 s	details
#3	WRONG ANSWER	0.04 s	details
#4	WRONG ANSWER	0.04 s	details
#5	WRONG ANSWER	0.04 s	details
#6	WRONG ANSWER	0.04 s	details
#7	WRONG ANSWER	0.04 s	details
#8	WRONG ANSWER	0.04 s	details
#9	WRONG ANSWER	0.04 s	details
#10	WRONG ANSWER	0.04 s	details
#11	WRONG ANSWER	0.04 s	details
#12	WRONG ANSWER	0.04 s	details
#13	WRONG ANSWER	0.04 s	details
#14	WRONG ANSWER	0.04 s	details
#15	WRONG ANSWER	0.04 s	details
#16	WRONG ANSWER	0.04 s	details
#17	WRONG ANSWER	0.04 s	details
#18	WRONG ANSWER	0.04 s	details
#19	RUNTIME ERROR	0.06 s	details
#20	WRONG ANSWER	0.04 s	details
#21	RUNTIME ERROR	0.06 s	details
#22	WRONG ANSWER	0.04 s	details
#23	WRONG ANSWER	0.04 s	details
#24	WRONG ANSWER	0.04 s	details
#25	WRONG ANSWER	0.04 s	details
#26	WRONG ANSWER	0.04 s	details
#27	WRONG ANSWER	0.04 s	details
#28	WRONG ANSWER	0.04 s	details
#29	RUNTIME ERROR	0.06 s	details
#30	WRONG ANSWER	0.04 s	details
#31	RUNTIME ERROR	0.06 s	details
#32	RUNTIME ERROR	0.06 s	details
#33	RUNTIME ERROR	0.06 s	details
#34	RUNTIME ERROR	0.06 s	details
#35	RUNTIME ERROR	0.06 s	details
#36	WRONG ANSWER	0.04 s	details
#37	RUNTIME ERROR	0.06 s	details
#38	WRONG ANSWER	0.04 s	details
#39	RUNTIME ERROR	0.06 s	details
#40	RUNTIME ERROR	0.06 s	details
#41	RUNTIME ERROR	0.06 s	details
#42	RUNTIME ERROR	0.07 s	details
#43	RUNTIME ERROR	0.07 s	details
#44	RUNTIME ERROR	0.06 s	details
#45	RUNTIME ERROR	0.06 s	details
#46	RUNTIME ERROR	0.07 s	details
#47	RUNTIME ERROR	0.07 s	details
#48	RUNTIME ERROR	0.07 s	details
#49	RUNTIME ERROR	0.07 s	details
#50	RUNTIME ERROR	0.07 s	details
#51	RUNTIME ERROR	0.06 s	details
#52	RUNTIME ERROR	0.07 s	details
#53	RUNTIME ERROR	0.07 s	details
#54	RUNTIME ERROR	0.07 s	details
#55	RUNTIME ERROR	0.07 s	details
#56	RUNTIME ERROR	0.07 s	details
#57	RUNTIME ERROR	0.07 s	details
#58	RUNTIME ERROR	0.07 s	details
#59	RUNTIME ERROR	0.07 s	details
#60	RUNTIME ERROR	0.07 s	details
#61	RUNTIME ERROR	0.07 s	details
#62	RUNTIME ERROR	0.13 s	details
#63	RUNTIME ERROR	0.13 s	details
#64	RUNTIME ERROR	0.14 s	details
#65	RUNTIME ERROR	0.13 s	details
#66	RUNTIME ERROR	0.13 s	details
#67	RUNTIME ERROR	0.14 s	details
#68	RUNTIME ERROR	0.13 s	details
#69	RUNTIME ERROR	0.14 s	details
#70	RUNTIME ERROR	0.14 s	details
#71	RUNTIME ERROR	0.14 s	details

Code

n = int(input())
ids = []
for _ in range(n):
    ids.append(input())
ids.sort()

def compare(j=0):
    if j >= len(ids)-1:
        return ids.pop()
    s1 = ids[j]
    s2 = ids[j+1]
    if s1[0] == s2[len(s1)]:
        return compare(j+1)
    elif s1[0] < s2[len(s1)]:
        return ids.pop(j)
    else:
        return ids.pop(j+1)
    
res = ""
while (len(ids) > 1):
    s1 = ids[0]
    s2 = ids[1]
    print(s1,s2)
    if len(s1) != len(s2) and s2[:len(s1)]==s1:    
        res += compare()
    else:
        res += s1
        ids.pop(0)
        continue
    print(res)
res += ids.pop()
print(res)

Test details

Test 1

Verdict: ACCEPTED

input
`1 gl` view save

correct output
`gl` view save

user output
`gl` view save

Test 2

Verdict: WRONG ANSWER

input
`2 adedf ff` view save

correct output
`adedfff` view save

user output
`adedf ff adedfff` view save

Test 3

Verdict: WRONG ANSWER

input
`2 jb lj` view save

correct output
`jblj` view save

user output
`jb lj jblj` view save

Test 4

Verdict: WRONG ANSWER

input
`2 qlipb sr` view save

correct output
`qlipbsr` view save

user output
`qlipb sr qlipbsr` view save

Test 5

Verdict: WRONG ANSWER

input
`3 f llk onfj` view save

correct output
`fllkonfj` view save

user output
`f llk llk onfj fllkonfj` view save

Test 6

Verdict: WRONG ANSWER

input
`3 jaeo mob nk` view save

correct output
`jaeomobnk` view save

user output
`jaeo mob mob nk jaeomobnk` view save

Test 7

Verdict: WRONG ANSWER

input
`3 nemlo psqhy sg` view save

correct output
`nemlopsqhysg` view save

user output
`nemlo psqhy psqhy sg nemlopsqhysg` view save

Test 8

Verdict: WRONG ANSWER

input
`4 dia eh fbcae gf` view save

correct output
`diaehfbcaegf` view save

user output
`dia eh eh fbcae fbcae gf diaehfbcaegf` view save

Test 9

Verdict: WRONG ANSWER

input
`4 c cbfaa egbg fc` view save

correct output
`cbfaacegbgfc` view save

user output
`c cbfaa cbfaa c egbg egbg fc cbfaacegbgfc` view save

Test 10

Verdict: WRONG ANSWER

input
`4 cbc cdd ceed dbeea` view save

correct output
`cbccddceeddbeea` view save

user output
`cbc cdd cdd ceed ceed dbeea cbccddceeddbeea` view save

Test 11

Verdict: WRONG ANSWER

input
`4 bfec bgbaf fcg fdbbg` view save

correct output
`bfecbgbaffcgfdbbg` view save

user output
`bfec bgbaf bgbaf fcg fcg fdbbg bfecbgbaffcgfdbbg` view save

Test 12

Verdict: WRONG ANSWER

input
`5 aoefh ge imgjj kmj ...` view save

correct output
`aoefhgeimgjjkmjmhhi` view save

user output
`aoefh ge ge imgjj imgjj kmj kmj mhhi aoefhgeimgjjkmjmhhi` view save

Test 13

Verdict: WRONG ANSWER

input
`5 bcbec ei fdigc ilabd ...` view save

correct output
`bcbeceifdigcilabdlg` view save

user output
`bcbec ei ei fdigc fdigc ilabd ilabd lg bcbeceifdigcilabdlg` view save

Test 14

Verdict: WRONG ANSWER

input
`5 a d db glfff ...` view save

correct output
`adbdglfffih` view save

user output
`a d d db adb d glfff glfff ih ...` view save

Test 15

Verdict: WRONG ANSWER

input
`5 ab d ebhin k ...` view save

correct output
`abdebhinknab` view save

user output
`ab d d ebhin ebhin k k nab abdebhinknab` view save

Test 16

Verdict: WRONG ANSWER

input
`5 fasgx o oezws qua ...` view save

correct output
`fasgxoezwsoquaspfd` view save

user output
`fasgx o o oezws fasgxoezws o qua qua spfd ...` view save

Test 17

Verdict: WRONG ANSWER

input
`5 bcggd dcg e fc ...` view save

correct output
`bcggddcgefcg` view save

user output
`bcggd dcg dcg e e fc fc g bcggddcgefcg` view save

Test 18

Verdict: WRONG ANSWER

input
`5 cmo cx hftbb mil ...` view save

correct output
`cmocxhftbbmiltksr` view save

user output
`cmo cx cx hftbb hftbb mil mil tksr cmocxhftbbmiltksr` view save

Test 19

Verdict: RUNTIME ERROR

input
`5 ab ababa b ca ...` view save

correct output
`ababaabbcaccb` view save

user output
`ab ababa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 20

Verdict: WRONG ANSWER

input
`5 o rjj sfj ti ...` view save

correct output
`orjjsfjtiw` view save

user output
`o rjj rjj sfj sfj ti ti w orjjsfjtiw` view save

Test 21

Verdict: RUNTIME ERROR

input
`5 a aa aaa abbab ...` view save

correct output
`aaaaaaabbabba` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 22

Verdict: WRONG ANSWER

input
`10 aoefh f ge hlmgh ...` view save

correct output
`aoefhfgehlmghimgjjjkmjmhhinmol...` view save

user output
`aoefh f f ge ge hlmgh hlmgh imgjj imgjj j ...` view save

Test 23

Verdict: WRONG ANSWER

input
`10 bcbec cjjil dbigk ei ...` view save

correct output
`bcbeccjjildbigkeifdigcgfbikfil...` view save

user output
`bcbec cjjil cjjil dbigk dbigk ei ei fdigc fdigc gfb ...` view save

Test 24

Verdict: WRONG ANSWER

input
`10 a cij d db ...` view save

correct output
`acijdbddhhekcgibfgglfffihkg` view save

user output
`a cij cij d d db acijdb d dhh ...` view save

Test 25

Verdict: WRONG ANSWER

input
`10 ab d ebhin fk ...` view save

correct output
`abdebhinfkgjdinaiodgkacknab` view save

user output
`ab d d ebhin ebhin fk fk gjd gjd ina ...` view save

Test 26

Verdict: WRONG ANSWER

input
`10 buywl fasgx gb jzpek ...` view save

correct output
`buywlfasgxgbjzpekoezwsoquaspfd...` view save

user output
`buywl fasgx fasgx gb gb jzpek jzpek o o oezws ...` view save

Test 27

Verdict: WRONG ANSWER

input
`10 acg bcggd dcg dede ...` view save

correct output
`acgbcggddcgdedeefcfdbbfgabbg` view save

user output
`acg bcggd bcggd dcg dcg dede dede e e f ...` view save

Test 28

Verdict: WRONG ANSWER

input
`10 cmo cx dpr dtir ...` view save

correct output
`cmocxdprdtirhftbbmfmiltksrttkb...` view save

user output
`cmo cx cx dpr dpr dtir dtir hftbb hftbb mf ...` view save

Test 29

Verdict: RUNTIME ERROR

input
`10 ab ababa abbc b ...` view save

correct output
`ababaababbcbbbcaccbcccccc` view save

user output
`ab ababa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 30

Verdict: WRONG ANSWER

input
`10 dmq gl j jqso ...` view save

correct output
`dmqgljjqsoorjjsfjtiulvw` view save

user output
`dmq gl gl j j jqso dmqglj jqso o ...` view save

Test 31

Verdict: RUNTIME ERROR

input
`10 a aa aaa abbab ...` view save

correct output
`aaaaaaabbabbabbabbabbbbbabbbbb` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 32

Verdict: RUNTIME ERROR

input
`100 aa acmfac afmolcn alllbndbli ...` view save

correct output
`aaacmfacafmolcnalllbndbliamdal...` view save

user output
`aa acmfac acmfac afmolcn afmolcn alllbndbli alllbndbli amdalfoklc amdalfoklc aoefhlmhh ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 33

Verdict: RUNTIME ERROR

input
`100 a acjgj ae aegdb ...` view save

correct output
`aacjgjaeaegdbafcbahledfchagaja...` view save

user output
`a acjgj a acjgj ae ae aegdb aacjgjae ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 34

Verdict: RUNTIME ERROR

input
`100 a aah abaeeaifc abajl ...` view save

correct output
`aaahabaeeaifcabajlaehaejcdegka...` view save

user output
`a aah aah a abaeeaifc aaha abaeeaifc abajl ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 35

Verdict: RUNTIME ERROR

input
`100 a aa abg abndfmmmk ...` view save

correct output
`aaaabgabndfmmmkacggjdeacogeada...` view save

user output
`a aa aa a abg aaa abg abndfmmmk ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 36

Verdict: WRONG ANSWER

input
`100 afn aic ajrkgzldb amcyqyh ...` view save

correct output
`afnaicajrkgzldbamcyqyhandanxhj...` view save

user output
`afn aic aic ajrkgzldb ajrkgzldb amcyqyh amcyqyh and and anxhjoe ...` view save

Test 37

Verdict: RUNTIME ERROR

input
`100 aacdeffdd abaacbae abfbbff ac ...` view save

correct output
`aacdeffddabaacbaeabfbbffacacbg...` view save

user output
`aacdeffdd abaacbae abaacbae abfbbff abfbbff ac ac acbgff aacdeffddabaacbaeabfbbffac ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 38

Verdict: WRONG ANSWER

input
`100 abnfxhutgk ajkdoqmdqp asxeblm badpwpsqhn ...` view save

correct output
`abnfxhutgkajkdoqmdqpasxeblmbad...` view save

user output
`abnfxhutgk ajkdoqmdqp ajkdoqmdqp asxeblm asxeblm badpwpsqhn badpwpsqhn bhwqfmat bhwqfmat biqhdvi ...` view save

Test 39

Verdict: RUNTIME ERROR

input
`100 a aa aaaaacaca aaaabcabc ...` view save

correct output
`aaaaaaaacacaaaaabcabcaaabaaaab...` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 40

Verdict: RUNTIME ERROR

input
`100 a aiesfhkro aivvkdc ajrtj ...` view save

correct output
`aaiesfhkroaivvkdcajrtjaqfnivlb...` view save

user output
`a aiesfhkro a aiesfhkro aivvkdc aivvkdc ajrtj ajrtj aqfnivl ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 41

Verdict: RUNTIME ERROR

input
`100 a aa aaaa aaaaa ...` view save

correct output
`aaaaaaaaaaaaaaaaaaaaaaaaaaabab...` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  [Previous line repeated 1 more time]
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 42

Verdict: RUNTIME ERROR

input
`200 a aa abbhjifdb acmfac ...` view save

correct output
`aaaabbhjifdbacmfacadiadnhkaehh...` view save

user output
`a aa aa a abbhjifdb aaa abbhjifdb acmfac ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 43

Verdict: RUNTIME ERROR

input
`200 a aa abihiahg acjgj ...` view save

correct output
`aaaabihiahgacjgjadaeaegdbafcba...` view save

user output
`a aa aa a abihiahg aaa abihiahg acjgj ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 44

Verdict: RUNTIME ERROR

input
`200 a aah abaeeaifc abajl ...` view save

correct output
`aaahabaeeaifcabajlaehaejcdegka...` view save

user output
`a aah aah a abaeeaifc aaha abaeeaifc abajl ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 45

Verdict: RUNTIME ERROR

input
`200 a aa aan abg ...` view save

correct output
`aaaaanabgabndfmmmkacggjdeacoge...` view save

user output
`a aa aa a aan` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 46

Verdict: RUNTIME ERROR

input
`200 ad aegewtfc afn aic ...` view save

correct output
`adaegewtfcafnaicajrkgzldbamcyq...` view save

user output
`ad aegewtfc aegewtfc afn afn aic aic ajrkgzldb ajrkgzldb amcyqyh ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 47

Verdict: RUNTIME ERROR

input
`200 a aa aacdeffdd aaeceaeb ...` view save

correct output
`aaaaacdeffddaaeceaebabaacbaeab...` view save

user output
`a aa aa a aacdeffdd` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 48

Verdict: RUNTIME ERROR

input
`200 abnfxhutgk aghv ajkdoqmdqp ajpvvalnu ...` view save

correct output
`abnfxhutgkaghvajkdoqmdqpajpvva...` view save

user output
`abnfxhutgk aghv aghv ajkdoqmdqp ajkdoqmdqp ajpvvalnu ajpvvalnu akdmlbddox akdmlbddox aosde ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 49

Verdict: RUNTIME ERROR

input
`200 a aa aaaaacaca aaaabcabc ...` view save

correct output
`aaaaaaaacacaaaaabcabcaaaacbcaa...` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 50

Verdict: RUNTIME ERROR

input
`200 a abam aiesfhkro aivvkdc ...` view save

correct output
`aabamaiesfhkroaivvkdcajrtjakam...` view save

user output
`a abam a abam aiesfhkro aiesfhkro aivvkdc aivvkdc ajrtj ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 51

Verdict: RUNTIME ERROR

input
`200 a aaicd acbjfaj achddjj ...` view save

correct output
`aaaicdacbjfajachddjjacifadaecf...` view save

user output
`a aaicd` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 52

Verdict: RUNTIME ERROR

input
`1000 a aa aaccbkcd aaj ...` view save

correct output
`aaaaaccbkcdaajaanabaabanikjabb...` view save

user output
`a aa aa a aaccbkcd` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 53

Verdict: RUNTIME ERROR

input
`1000 a aa aabecajcf aabg ...` view save

correct output
`aaaaabecajcfaabgaabjllgdlkaadg...` view save

user output
`a aa aa a aabecajcf` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 54

Verdict: RUNTIME ERROR

input
`1000 a aa aablaga aah ...` view save

correct output
`aaaaablagaaahaajaaklkjjababaee...` view save

user output
`a aa aa a aablaga` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 55

Verdict: RUNTIME ERROR

input
`1000 a aa aagjd aajdlmacjn ...` view save

correct output
`aaaaagjdaajdlmacjnaakjdngdfaal...` view save

user output
`a aa aa a aagjd aaaagjd a aajdlmacjn` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 56

Verdict: RUNTIME ERROR

input
`1000 a aalguz abcce abggxup ...` view save

correct output
`aaalguzabcceabggxupabujabxldxy...` view save

user output
`a aalguz` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 57

Verdict: RUNTIME ERROR

input
`1000 a aa aaabaaaaf aaaeb ...` view save

correct output
`aaaaaabaaaafaaaebaabeadaabfffd...` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 58

Verdict: RUNTIME ERROR

input
`1000 a aamuthxggq abnfxhutgk adaumgqm ...` view save

correct output
`aaamuthxggqabnfxhutgkadaumgqma...` view save

user output
`a aamuthxggq` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 59

Verdict: RUNTIME ERROR

input
`1000 a aa aaa aaaa ...` view save

correct output
`aaaaaaaaaaaaaaaaaaaaaaaaaaabaa...` view save

user output
`a aa aaaaaa a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  [Previous line repeated 2 more times]
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 60

Verdict: RUNTIME ERROR

input
`1000 a aanmhqqnpc ab abam ...` view save

correct output
`aaanmhqqnpcababamabginwqvvacba...` view save

user output
`a aanmhqqnpc` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 61

Verdict: RUNTIME ERROR

input
`1000 a aa aaaca aae ...` view save

correct output
`aaaaaacaaaeaaekcaagjeahdaahhdf...` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 62

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaagle ...` view save

correct output
`aaaaaaaaaagleaaabaaabiaaaaccgh...` view save

user output
`a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 63

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaagf ...` view save

correct output
`aaaaaaaaaagfaaaaihlblgaaaalkll...` view save

user output
`a aa aaaagf a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 64

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaa ...` view save

correct output
`aaaaaaaaaaaaaabkaaaaelbjbaaaaf...` view save

user output
`a aa aaaa a aa aaaaaaaabk a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 65

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaa ...` view save

correct output
`aaaaaaaaaaaaaahleaaaajaaabaaab...` view save

user output
`a aa aaaa a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 66

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaacxrqz ...` view save

correct output
`aaaaaaaaacxrqzaaahaaaahaaaplto...` view save

user output
`a aa aaa a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 67

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaa ...` view save

correct output
`aaaaaaaaaaaaaaaaaaaaaadbaaaaaa...` view save

user output
`a aa aaaaaaadb a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  [Previous line repeated 2 more times]
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 68

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaail ...` view save

correct output
`aaaaaaaaailaaaitehaeaaaitxaaam...` view save

user output
`a aa aaa a aa aaaaaail a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 69

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaa ...` view save

correct output
`aaaaaaaaaaaaaaabghaaaabcaffaaa...` view save

user output
`a aa aaaaabgh a aa aaaaabghaaaa a aa ...` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 70

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaaggo ...` view save

correct output
`aaaaaaaaaaggoaaacwpgjkvaaaftbl...` view save

user output
`a aa aaaaggo a aa aaaaggoaaa a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Test 71

Verdict: RUNTIME ERROR

input
`100000 a aa aaa aaaa ...` view save

correct output
`aaaaaaaaaaaaaabaaaagkaaabaaabb...` view save

user output
`a aa aaaa a aa aaaaaaaab a aa` view save

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 25, in <module>
    res += compare()
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 13, in compare
    return compare(j+1)
  File "/box/input/code.py", line 12, in compare
    if s1[0] == s2[len(s1)]:
IndexError: string index out of range

Aalto Competitive Programming 2026 - wk5 - Mon

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