#include <iostream>

using namespace std;

int main()
{
  int square(int* x);
  int x = 2;
  cout << "Before calling square(), x is " << x << endl;
  int x2 = square(&x);
  cout << "The square is " << x2 << endl;
  cout << "After calling square(), x is " << x << endl; 
  return 0;
}

int square(int* x)
{
  *x = (*x) * (*x);
  return(*x);
}