[프로그래머스] 콜라츠 추측

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