class Solution
{
public:
void push(int node) {
stack1.push(node);
}
int pop() {
int temp;
while(stack2.empty()){
while(!stack1.empty()){
temp = stack1.top();
stack1.pop();
stack2.push(temp);
}
}
temp = stack2.top();
stack2.pop();
return temp;
}
private:
stack<int> stack1;
stack<int> stack2;
};