using System;

​

public class Prime

{

    public static void Main()

    {

        int i,n,m=0,flag=0;

        Console.Write("Enter a Number to check:");

        n=int.Parse(Console.ReadLine());

        m=n/2;

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

        {

            if(n%i==0)

            {

                Console.Write("This is not a prime number");

            flag=1;

            break;

            }

        }

            if(flag==0)

                Console.Write("this is a prime number");

    }

}