using System;

public class Program

{

    public static void Main()

    {

        int[] nums1 = new int[] {2, 7, 6, 3, 9, 5, 10, 8};

        int num = 15;

        Couples(nums1, num); 

    }

    public static void Couples(int[] nums, int number)

    {

        for(int i = 0; i < nums.Length; i++)

        {

            for(int j = 0; j < nums.Length; j++)

            {

                if(nums[i] + nums[j] == number)

                {

                    Console.WriteLine("\t({0},{1})\n", nums[i], nums[j]);

                    nums[i] = 0 - number; nums[j] = 0 - number;

                }

            }

        }

    }

}