PrintSequence

using System;

//Write a program that prints the first 10 members of the sequence: 2, -3, 4, -5, 6, -7, ...

class PrintSequence
{
    static void Main()
    {
        for (int i = 2; i < 13; i++)
        {
            if (i % 2 != 0)
            {
                Console.Write("{0}, ", i * (-1));
            }
            else
            {
                Console.Write("{0}, ", i);
            }
        }
    }
}