#include <iostream>
using namespace std;
class Stack {
public:
   enum { MaxStack = 5 };
   void init() { top = -1; }
   void push( int n ) {
      if ( isFull() ) {
        errMsg( "Full stack. Can't push." );
        return;
      }
      arr[ ++top ] = n;
   }
   int pop() {
      if ( isEmpty() ) {
        errMsg( "Empty stack. Popping dummy value." );
        return dummy_val;
      }
      return arr[ top-- ];
   }
   bool isEmpty() { return top < 0; }
   bool isFull() { return top >= MaxStack - 1; }
   void dump() {
     cout << "Stack contents, top to bottom:\n";
     for ( int i = top; i >= 0; i-- )
       cout << '\t' << arr[ i ] << '\n';
   }
private:
   void errMsg( const char* msg ) const {
      cerr << "\n*** Stack operation failure: " << msg << '\n';
   }
   int top;
   int arr[ MaxStack ];
   int dummy_val;
};