PRIME OR NOT ?

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace prime

{

    class Program

    {

       static void Main(string[] args)

       {

           int i,number,flag=0;

           number=Int32.Parse(Console.ReadLine());

          // while (i <= number)

           for (i = 2; i < number;i++ )

           {

               if (number % i == 0)

               {

                   flag = 1;

               }

            

           }

           if (flag == 1)

           {

               Console.WriteLine("number is not a prime no ");

           }

           else

           {

               Console.WriteLine("no is a prime no ");

           }

         

       

       }

    }

}