#include <iostream>

 #include <vector>

 #include <algorithm>

 #include <queue>

 #include <stack>

 #include <string>

 #include <fstream>

 #include <map>

 #include <set>

 using namespace std;

 void insertbottom(stack<int> &S, int top) {

     if (S.empty()) S.push(top);

     else {

         int tmp = S.top();

         S.pop();

         insertbottom(S, top);

         S.push(tmp);

     }

 }

 void reversestack(stack<int> &S) {

     if (S.empty()) return;

     int top = S.top();

     S.pop();

     reversestack(S);

     insertbottom(S, top);

 }

 int main() {

     stack<int> S;

     S.push();

     S.push();

     S.push();

     S.push();

     reversestack(S);

     while (!S.empty()) {

         cout << S.top() << endl;

         S.pop();

     }

     return ;

 }