import sys
sys.setrecursionlimit(100000000)
input = sys.stdin.readline
MOD = 10 ** 9 + 7
INF = 10 ** 15
from itertools import permutations
def main():
    N = int(input())
    shiritori = ['a']

    itr = permutations('abcedfghiijklmnopqrstubwxyz',18)
    before = ''.join(next(itr))
    for i in range(N - 1):
        if i == N - 2:
            shiritori.append(chr(i%26 + 97) + 'n')
            break
        word = chr(i%26 + 97)
        if word == 'a':
            before = ''.join(next(itr))
        word += before
        word += chr((i + 1)%26 + 97)
        shiritori.append(word)
    print('\n'.join(shiritori))
if __name__ == '__main__':
    main()