Implementing Stack Using Queue

Implementing stack using two queues, where we push element to q2 and then move pop and add all the to q1. Swap q2 to q1 to proceed with pop or another push operation.

Input:
push(1)
push(2)
push(3)

pop()
pop()
pop()
pop()

Output:
1 :3
2 :2
3 :1
Queue Empty
4 :null