Monistus

s = list(input()[::-1])
rs = []
n = len(s)
m = 0
 
pos = n-1
 
s.append((100000)*['0'])
 
while pos >= 0:
  if '1'<=s[pos]<='9':
    num = int(s[pos])
    for i in range(num):
      s[pos+num-i-1] = s[pos-i-1]
    pos += num-1
    continue
  rs.append(s[pos])
  pos -= 1
  m += 1
 
for i in range(m):
  print(rs[i], end="")

Test 1

Group: 1, 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 1, 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: ACCEPTED

Test 6

Group: 1, 2

Verdict: ACCEPTED

Test 7

Group: 1, 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 8

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 9

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 10

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 13

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range

Test 14

Group: 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "/box/input/code.py", line 14, in <module>
    s[pos+num-i-1] = s[pos-i-1]
IndexError: list assignment index out of range