n = int(input())
alphabet = 'abcdefghijklmopqrstuvwxyz'

for i in range(n-1):
    s = 'a'
    tmp = i
    s += alphabet[tmp%25]
    tmp = int(tmp/25)
    s += alphabet[tmp%25]
    tmp = int(tmp/25)
    s += alphabet[tmp%25]
    tmp = int(tmp/25)
    s += alphabet[tmp%25]
    s += 'a'
    s = s[::-1]
    print(s)
print('an')