PrintSequence

using System;

class PrintSequence
{
    static void Main()
    {
        for (int i = 2; i <= 11; i++)
        {
            if (i % 2 == 0) //if i is even print i
            {
                Console.Write(i + ",");
            }
            else //if i is odd print its negative value
            {
                Console.Write(i * (-1) + ",");
            }
        }
    }
}