using System;

using System.Collections.Generic;

using System.Linq;

​

namespace Test

{

    class MyClass

    {

        static void FindParings(int[] values, int target)

        {

            List<int> output = new List<int>();

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

            {

                if (output.Contains(values[i]))

                    continue;

                for (int j = i + 1; j < values.Length; j++)

                {

                    if (values[i] + values[j] == target)

                    {

                        output.Add(values[i]);

                        output.Add(values[j]);

                    }

                }

            }

​

            for (int x = 0; x < output.Count(); x++)

            {

                if ((x + 1) % 2 == 0)

                    Console.WriteLine("(" + output[x - 1] + " " + output[x] + ")");

            }

        }

​

        static void Main(string[] args)

        {

            int[] values = [5, 2, 2, 2, 5, 17, -1, 20];

            var targetValue = 22;

            FindParings(values, targetValue);

        }

    }

}