using System;

public class Program

{

    public static void Main()

    {

        int flag;

        Console.WriteLine("Enter number to check prime: ");

        int num = Convert.ToInt16(Console.ReadLine());

        flag = prime(num);

        if (flag == 0)

        {

            Console.WriteLine("Number is not prime.");  

        }

        else

        {

            Console.WriteLine("Number is prime.");

        }

    }

    static int prime(int num)

    {

        int flag = 0;

        for (int i=2;i<=num/2;i++)

        {

            if (num%i==0)

            {

                flag = 0;

                break;

            }

            else

            {

                flag = 1;

            }

        }

        return flag;

    }

}