import re
from string import ascii_lowercase
from typing import Optional


class SelfShiritori:
    def __init__(self) -> None:
        self.start_letter_state = {letter: 0 for letter in ascii_lowercase}

    def create_word(self, start: str, end: Optional[str] = None) -> str:
        return_str = start
        return_str += chr(97 +
                          (self.start_letter_state[start] // (26 ** 3)) % 26)
        return_str += chr(97 +
                          (self.start_letter_state[start] // (26 ** 2)) % 26)
        return_str += chr(97 + (self.start_letter_state[start] // 26 % 26))
        return_str += chr(97 + (self.start_letter_state[start] % 26))
        if end is not None:
            return_str += end
        else:
            return_str += chr((ord(start)-96) % 26 + 97)

        self.start_letter_state[start] += 1
        return return_str


def main():
    n = int(input())
    shiritori = SelfShiritori()
    for idx in range(n-1):
        print(shiritori.create_word(chr(97 + idx % 26), ))

    print(shiritori.create_word(chr(97 + (n-1) % 26), "n"))


if __name__ == "__main__":
    main()