#include<iostream.h>

void main()
{
   int i ;
   int j ;
   cout << "Enter i: " ;
   cin >> i ;
   cout << "Enter j (greater than i): " ;
   cin >> j ;
   if ( i>j )
   {
      cout << "i must be less than or equal to j " ;
   }
   else
   {
      cout << "there are " ;
      cout << j-i+1 ;
      cout << " fence posts between " ;
      cout << i ;
      cout << " and "  ;
      cout <<  j ;
   }
   cout << endl ;
}