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())
    if N == 1:
        print('n')
        return
    shiritori = ['a']

    itr = permutations('abcedfghijklmnopqrstuvwxyz',18)
    before = ''.join(next(itr))
    i = 0
    length = 1
    while length < N:
        if length == N - 1:
            shiritori.append(chr(i%26 + 97) + 'n')
            break
        if i%26 == 13:
            i += 1
            continue
        word = chr(i%26 + 97)
        if word == 'a':
            before = ''.join(next(itr))
        word += before
        if i%26 == 12:
            word += chr((i + 2)%26 + 97)
        else:
            word += chr((i + 1)%26 + 97)
        shiritori.append(word)
        i += 1
        length += 1
    print('\n'.join(shiritori))
if __name__ == '__main__':
    main()