삼총사

def solution(number):

    answer = 0

    for i in range(len(number)-2):

        for j in range(i+1,len(number)-1):

            for k in range(j+1,len(number)):

                if number[i]+number[j]+number[k] == 0:

                    answer += 1

    print(answer)

    return answer

solution([-1, 1, -1, 1])