Homework 5 Problem 8

using System;

namespace PrimeNumberCheck
{
    class Program
    {
        static void Main()
        {
            Console.Write("Enter the number: ");
            int n = int.Parse(Console.ReadLine());

            if (n <= 1) { Console.WriteLine("false"); return; }
            for (int i = 2; i <= Math.Sqrt(n); i++)
            {
                if ((n % i == 0 && n != i))
                {
                    Console.WriteLine("false"); return;
                }
            }
            Console.WriteLine("true");
        }
    }
}