Merkkijono

n=int(input())
#                                                                 16
alph=["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s"]
out=""
save=""

for x in range(n):
    save=out
    out=""
    i=0
    if(x==0):
        out=alph[0]
    else:
        for c in save:
            if(c==alph[x-1]):
                out+=alph[x]+c+alph[x]
            else:
                out+=c

print(out)
        

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED