import random
import string

n = int(input())
a = []


def gen(x):
    while True:
        s = ''.join([
            random.choice(string.ascii_lowercase)
            for _ in range(random.randint(1, 18))
        ])
        s = x + s
        if s[-1] != 'n' and s not in a:
            a.append(s)
            break
    return s


x = 'a'
for i in range(n - 1):
    s = gen(x)
    x = s[-1]
    print(s)
s = gen(x)
print(s + 'n')