| 11 | pass |
| 12 | |
| 13 | class Stack: |
| 14 | def __init__(self): |
| 15 | self.__stack = list() |
| 16 | def __len__(self): |
| 17 | return len(self.__stack) |
| 18 | def push(self, item): |
| 19 | self.__stack.append(item) |
| 20 | def pop(self): |
| 21 | return self.__stack.pop() |
| 22 | |
| 23 | ################################################################################ |
| 24 |