using System;
public class Program
{
public static void Main()
int n, i, m=0, flag=0;
Console.Write("Enter the Number to check Prime: ");
//read number
n = int.Parse(Console.ReadLine());
//divide it by 2 and get remainder
m=n/2;
//loop until the remainder is reach, check if it is divisble
for(i = 2; i <= m; i++)
// if divisible by any number from 2 to m, then it is not prime
if(n % i == 0)
Console.WriteLine("Number is not Prime.");
flag=1;
break;
}
// if flag =0, means,above code when flag =1 is assigned is not executed and hence it is prime number
if (flag==0){
Console.WriteLine("Number is Prime.");