import random

def aaa():
    while len(shiritori)<a:
        c = random.randint(1,18)
        for i in range(c):
            b = random.choice("abcdefghijklmopqrstuvwxyz")
            global word
            word = word + b

            if i == c-1:
                if len(shiritori)==a-1:
                    word = word+'n'
                print(word)
                shiritori.add(word)
                word = b

a = int(input())
word = random.choice("abcdefghijklmopqrstuvwxyz")
shiritori = set()
aaa()