def getNonN(k):
    s = []
    b = "{:026b}".format(k)
    for i, n in enumerate(b):
        if n == "1":
            s.append(string.ascii_letters[i])
    return "".join(s).lower()

def solve(N):
    ret = []
    for k in range(0, N):
        st = "a" + getNonN(k) + "a"
        ret.append(st)
    ret[-1] = ret[-1] + "n"
    return ret

if __name__ == "__main__":
    [print(a) for a in solve(int(input()))]