Enumerating k-mers Lexicographically (ROSALIND LEXF)

Given: A collection of at most 10 symbols defining an ordered alphabet, and a positive integer n (n≤10).

Return: All strings of length n that can be formed from the alphabet, ordered lexicographically.

s = input()
n = int(input())

alphabet = s.split(' ')

def cycle(res, k):
    if k > 1:
        new_res = []
        for r in range(len(res)):
            for i in alphabet:
                new_res.append(res[r] + i)
        return cycle(new_res, k-1)
    else:
        return res

for i in cycle(alphabet, n):
    print(i)