using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

namespace ConsoleApplication1

{

    public class Program

    {

        public static void Main()

        {

            Program p = new Program();

            long j=12520;

            while(j>= 12520)

            {

                //2520 

                bool result = p.Check(j);

                if (result==true)

                {

                    Console.WriteLine("True");

                    //break;

                    Console.ReadLine();

                }

                j++;

​

            }

        }

        public bool Check(long j)

        {

            long i = 1;

            while ((i >= 1) && (i <= 20))

            {

                long m = (j % i);

                if (m == 0)

                {

                    i++;

                }

                else

                    return false;

            }

            return true;

        }

    }

}

​

​