/* This version of runtime.ccp uses a do while loop to force the user
   to enter data which will not lead to a runtime error. */

#include<iostream.h>
#include<cmath>

void main() {

  int a,b;
  double x,y,z;

  do {
    cout << "Enter two distinct integers: ";
    cin >> a >> b;
  }
  while (a == b);

  //  At this point we know that a != b.

  x = 1./(a-b);
  cout << "1/(" << a << " - " << b << ") = " << x << endl;

  do {
    cout << "Enter a nonnegative real number: ";
    cin >> y;
  }
  while (y<0);
  
  // At this point we know that y >= 0.

  z = sqrt(y);
  cout << "The square root of " << y << " is " << z << endl;

}