using System;

using System.Collections.Generic;                                   

public class Program

{

    public static void Main()

    {

        List<int> numbers = new List<int>() {};

        for(int k = 1000; k <= 9999; k++) { 

         if(k * 14 % Math.Sqrt(k * 14) == 0){

          numbers.Add(k);

         } 

        }

         Console.WriteLine(numbers[numbers.Count-1]);

​

    }

}

​