package main

var stack1 [] int
var stack2 [] int

func Push(node int) {
	stack1 = append(stack1, node)
}

func Pop() int {
	for ; len(stack1) != 0; {
		stack2 = append(stack2, stack1[len(stack1) - 1])
		stack1 = stack1[:len(stack1) - 1]
	}
	res := stack2[len(stack2) - 1]
	stack2 = stack2[:len(stack2) - 1]
	for ; len(stack2) != 0; {
		stack1 = append(stack1, stack2[len(stack2) - 1])
		stack2 = stack2[:len(stack2) - 1]
	}
	return res
}