bufio_scanner = []


def fmt_scan() -> str:
    sc = bufio_scanner
    if len(sc) == 0:
        for v in reversed(input().split()):
            sc.append(v)
    return sc.pop()


def main():
    n = int(fmt_scan())

    for i in range(n - 1):
        ans = "a"
        k = i + 1
        while k > 0:
            ans += chr(ord("a") + k % 10)
            k //= 10
        ans += "a"
        print(ans)
    print("an")


main()