Triples of Latin Letters

def print_all_letter_combinations(N):
    letters = "abcdefghijklmnopqrstuvwxyz"

    for i in range(N):
        for j in range(N):
            for k in range(N):
                print(letters[i] + letters[j] + letters[k])

N = int(input())

print_all_letter_combinations(N)