using System;

public class Program

{

    public static void Main()

    {

        int[] numbers = new int[20] {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20};

        Random rnd = new Random();

        Console.WriteLine("Исходный массив");

        for (int i = 0; i < 20; i++)

        {

            numbers[i] 

            Console.Write("{0}", numbers[0-19]);

        }

         Console.WriteLine ("\nЧетные");

         for (int i = 0; i < 20; i++)

            {

            if (numbers[i] % 2 == 0);

            {

                Console.Write("{0}", numbers[i]);

            }

        }

    }

}