[프로그래머스/파이썬] 콜라츠 추측

-코드

def solution(num):
    answer = 0
    while num != 1:
        if answer >= 500:
            return -1
        if num % 2 == 0:
            num //= 2
        else:
            num = num * 3 + 1
        answer += 1
    return answer