import random

letters = 'abcdefghijklmopqrstuvwxyz'
n = int(input())
ans = "a"

for i in range(n-1):
    l = random.choices(letters, k=19)
    pre = ""
    for li in l:
        pre += li
    ans = ans[-1] + pre
    print(ans)
print(ans[-1] + "n")