#include <iostream>
using std::cout;
using std::cin;
using std::endl;

int main()
{
   int n, m, counter = 0;

   cout << "Enter n: ";
   cin >> n;
   cout << "Enter m: ";
   cin >> m;

   if(n >= m)
   {
      cout << "Invalid value" << endl;
   }
   else
   {
      while(n <= m)
      {
         if(n % 4 == 0)
         {
            counter++;
         }
         n++;
      }
   }

   cout << counter << " value" << (counter != 1 ? "s" : "") << endl;

   cin.get();
   return 0;
}

Вывод:

Enter n: 2000

Enter m: 2012

4 values

На Паскале:

program test;
var n, m, counter: integer;

begin
  write('Enter n: ');
  readln(n);
  write('Enter m: ');
  readln(m);
  counter := 0;
  while n <= m do
  begin
    if n mod 4=0 then
      counter := counter + 1;
    n := n + 1;
  end;
writeln(counter, ' values');
readln();
end.