from itertools import *

N = int(input())
S = list("abcdefghijklmnopqrstuvwxyz")
ans = []
cnt = 0
for tup in permutations(S, 10):
    if cnt != N - 1:
        ans.append("a" + "".join(tup) + "a")
    else:
        break
    cnt += 1
ans.append("an")
for i in ans:
    print(i)