Implement a last-in-first-out (LIFO) stack using only two queues.
Example 1:
Input:
["MyStack", "push", "push", "top", "pop", "empty"]
[[], [1], [2], [], [], []]
Output: [null, null, null, 2, 2, false]
Constraints:
1 <= x <= 9- At most
100 calls will be made.