Primes.cs

using System;

class SomePrimes
{
    static void Main()
    {
        Console.WriteLine("Enter a number to check if it's prime:");
        int prime = int.Parse(Console.ReadLine());
        if (prime <= 1)
        {
            Console.WriteLine("Your number is NOT prime.");
        }
        else if (prime == 2)
        {
            Console.WriteLine("Your number is prime.");
        }
        else if (prime % 2 == 0)
        {
            Console.WriteLine("Your number is NOT prime.");
        }
        else
        {
            bool isPrime = true;
            for (int i = 2; i <= prime - 1; i++)
            {
                if (prime % i == 0)
                {
                    isPrime = false;
                }
            }

            if (isPrime)
            {
                Console.WriteLine("Your number is prime.");
            }
            else
            {
                Console.WriteLine("Your number is NOT prime.");
            }
        }
    }
}