#include <iostream>
using namespace std;

const int SIZE = 10;

template <class StackType> class stack {
  StackType stck[SIZE];
  int tos;

public:
  stack() {
     tos = 0;
  }
    void push(StackType ob)
    {
      if(tos==SIZE) {
        cout << "Stack is full.\n";
        return;
      }
      stck[tos] = ob;
      tos++;
    }

    StackType pop()
    {
      if(tos==0) {
        cout << "Stack is empty.\n";
        return 0; // return null on empty stack
      }
      tos--;
      return stck[tos];
    }
};

int main() {
  stack<char> s1, s2;

  s1.push('a');
  s2.push('x');
  s1.push('b');
  s2.push('y');
  s1.push('c');
  s2.push('z');

  for(int i=0; i<3; i++)
     cout << "Pop s1: " << s1.pop() << "\n";
  for(int i=0; i<3; i++)
     cout << "Pop s2: " << s2.pop() << "\n";

  stack<double> ds1, ds2;

  ds1.push(1.1);
  ds2.push(2.2);
  ds1.push(3.3);
  ds2.push(4.4);
  ds1.push(5.5);
  ds2.push(6.6);

  for(int i=0; i<3; i++)
     cout << "Pop ds1: " << ds1.pop() << "\n";
  for(int i=0; i<3; i++)
     cout << "Pop ds2: " << ds2.pop() << "\n";

  return 0;
}