Stuck Numbers

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication6
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            string[] input = Console.ReadLine().Split(' ');
            List<List<string>> subsetGood = new List<List<string>>();
            double combinations = Math.Pow(2, n);
            for (int i = 0; i < combinations; i++)
            {
                int counter = 0;
                List<string> subset = new List<string>();
                for (int bitPosition = 0; bitPosition < n; bitPosition++)
                {

                    if ((i & (1 << bitPosition)) != 0)
                    {
                        subset.Add(input[bitPosition]);
                        counter++;
                    } // if bitPosition
                }// bitwise for
                if (counter == 4)
                {
                    subsetGood.Add(subset);
                }
            }// for with combinations
            foreach (var list in subsetGood)
            {
                List<List<string>> subsetTwoElementsGood = new List<List<string>>();
                double newCombinations = Math.Pow(2, 4);
            for (int i = 0; i < newCombinations; i++)
            {
                List<string> subset = new List<string>();
                int counter = 0;
                for (int bitPosition = 0; bitPosition < 4; bitPosition++)
                {
                    if ((i & (1 << bitPosition)) != 0)
                    {
                        subset.Add(list[bitPosition]);
                        counter++;
                    }
                }// for bitPosition2
                if (counter == 2)
                {
                    subsetTwoElementsGood.Add(subset);
                }// if counter = 2
            }// for new Combinations

                for (int p = 0; p < subsetTwoElementsGood.Count; p++)
                {
                    List<string> subset = new List<string>();
                    int checkFirstTwo = 0;
                    int checkSecondTwo = 0;
                    for (int check = 0; check < subsetTwoElementsGood.Count; check++)
                    {
                        if (check == p)
                        {
                            continue;
                        }

                        else
                        {
                            checkFirstTwo = int.Parse(subsetTwoElementsGood[p][0] + subsetTwoElementsGood[p][1]);
                            checkSecondTwo = int.Parse(subsetTwoElementsGood[check][0] + subsetTwoElementsGood[check][1]);
                            if ((checkFirstTwo == checkSecondTwo) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][1]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][1]))
                            {
                                Console.WriteLine("{0}|{1}={2}|{3}", subsetTwoElementsGood[p][0], subsetTwoElementsGood[p][1], subsetTwoElementsGood[check][0], subsetTwoElementsGood[check][1]);
                            }
                            else
                            {
                                checkFirstTwo = int.Parse(subsetTwoElementsGood[p][1] + subsetTwoElementsGood[p][0]);
                                checkSecondTwo = int.Parse(subsetTwoElementsGood[check][0] + subsetTwoElementsGood[check][1]);
                                if ((checkFirstTwo == checkSecondTwo) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][1]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][1]))
                                {
                                    Console.WriteLine("{0}|{1}={2}|{3}", subsetTwoElementsGood[p][1], subsetTwoElementsGood[p][0], subsetTwoElementsGood[check][0], subsetTwoElementsGood[check][1]);
                                }
                                else
                                {
                                    checkFirstTwo = int.Parse(subsetTwoElementsGood[p][1] + subsetTwoElementsGood[p][0]);
                                    checkSecondTwo = int.Parse(subsetTwoElementsGood[check][1] + subsetTwoElementsGood[check][0]);
                                    if ((checkFirstTwo == checkSecondTwo) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][1]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][1]))
                                    {
                                        Console.WriteLine("{0}|{1}={2}|{3}", subsetTwoElementsGood[p][1], subsetTwoElementsGood[p][0], subsetTwoElementsGood[check][1], subsetTwoElementsGood[check][0]);
                                    }
                                    else
                                    {
                                        checkFirstTwo = int.Parse(subsetTwoElementsGood[p][0] + subsetTwoElementsGood[p][1]);
                                        checkSecondTwo = int.Parse(subsetTwoElementsGood[check][1] + subsetTwoElementsGood[check][0]);
                                        if ((checkFirstTwo == checkSecondTwo) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][0] != subsetTwoElementsGood[check][1]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][0]) && (subsetTwoElementsGood[p][1] != subsetTwoElementsGood[check][1]))
                                        {
                                            Console.WriteLine("{0}|{1}={2}|{3}", subsetTwoElementsGood[p][0], subsetTwoElementsGood[p][1], subsetTwoElementsGood[check][1], subsetTwoElementsGood[check][0]);
                                        }
                                    }
                                }
                            }
                        }

                }

            }
            }// foreach
            //subsetTwoElementsGood.ForEach(t => Console.WriteLine(string.Join("..", t)));
        }
    }
}
// Ugly