#include <iostream>

using namespace std;


void f( int & x, int & y )
{
   x++; y++;
}

int main()
{
   int a = 4, b = 7, c = 8, d = 2;

   cout << "Call: f(a,b)" << endl;
   cout << "Before call: a = " << a << ", b = " << b  
        << ", c = " << c << ", d = " << d << endl;
   f( a, b );
   cout << "After  call: a = " << a << ", b = " << b  
        << ", c = " << c << ", d = " << d << endl << endl;

   cout << "Call: f(a,b)" << endl;
   cout << "Before call: a = " << a << ", b = " << b  
        << ", c = " << c << ", d = " << d << endl;
   f( c, d );
   cout << "After  call: a = " << a << ", b = " << b  
        << ", c = " << c << ", d = " << d << endl << endl;
}