16.Problem

using System;


namespace _16.Long_Sequence
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = 2;
            int b = -(a + 1);

            for (int i = 0; i < 500; i++)
            {
                Console.WriteLine(a);
                Console.WriteLine(b);

                a = a + 2;
                b = b - 2;


            }



        }
    }
}