int a = Convert.ToInt32(Console.ReadLine());    
            int b = a;
            int c = 0;
            int b = 2;
            while (a%b!=0 && B<=a-1)
            {
               b++;
               Console.WriteLine(b);
            }
            if(b == a)
            {
                Console.WriteLine("prím");
            }
            else
            {
                Console.WriteLine("nem prím");
            }
            Console.ReadKey();