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