Primes C#

/*
 * Created by SharpDevelop.
 * User: Admin
 * Date: 11/10/2021
 * Time: 6:28 AM
 *
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
using System;
using System.Diagnostics;

namespace SimplePrimes
{
    class Program
    {
        public static void Main(string[] args)
        {
            //bool[] nums;
            byte[] nums;
            int n, m, lim;
            Stopwatch elapsed;
            string yorn;

            Console.WriteLine("This program will search for prime numbers using a simple algorithm . . .");
            Console.Write("Enter max limit # and press ENTER (leave blank for default): ");
            lim = Convert.ToInt32("0" + Console.ReadLine());  // WE HAVE TO PUT THE 0 IN FRONT TO FORCE STUPID C# TO NOT HAVE ERROR IF INPUT IS BLANK...
            // C# SHOULD RETURN 0 FOR A BLANK STRING AND ONLY EXCEPTION ON NULL STRING, BUT I DIDN'T DESIGN THIS :P
            if (lim == 0)
                lim = 100000000;

            elapsed = new Stopwatch();
            elapsed.Start();
            //nums = new bool[lim + 1];
            nums = new byte[lim + 1];

            for (n = 2; n < Math.Sqrt(lim); n++)
            {
                if (nums[n] == 0)
                {
                    m = n * n;
                    while (m <= lim)
                    {
                        nums[m] = 1;
                        m += n;
                    }
                }
            }

            elapsed.Stop();
            Console.WriteLine("It took " + (elapsed.ElapsedMilliseconds / 1000.0).ToString() + " seconds to complete.");
            Console.Write("Do you want to print the results (Y/N)? ");
            yorn = Console.ReadLine();

            if (yorn == "Y" || yorn == "y")
            {
                m = 0;
                for (n = 2; n <= lim; n++)
                {
                    if(nums[n] == 0)
                    {
                        Console.WriteLine(n.ToString());
                        m++;
                    }
                }
                Console.WriteLine("Total primes = " + m.ToString());
                Console.WriteLine("");
                Console.Write("Press any key to end . . . ");
                Console.ReadKey(true);
            }
        }
    }
}