class Solution:
    def lemonadeChange(self, bills: List[int]) -> bool:
        five, ten = 0, 0
        for b in bills:
            if b == 5:
                five += 1
            elif b == 10:
                ten += 1
                if five > 0:
                    five -= 1
                else:
                    return False
            else:
                change = b - 5
                if change == 15 and five > 0 and ten > 0:
                    five -= 1
                    ten -= 1
                elif change == 15 and five >= 3:
                    five -= 3
                else:
                    return False
        return True

class Solution:
    def lemonadeChange(self, bills: List[int]) -> bool:
        five, ten = 0, 0
        for b in bills:
            if b == 5:
                five += 1
            elif b == 10:
                five, ten = five - 1, ten + 1
            elif ten > 0:
                five, ten = five - 1, ten - 1
            else:
                five -= 3
            if five < 0:
                return False
        return True