Stuck Numbers

using System;

public class StuckNumbers
{
    public static void Main()
    {
        Console.ReadLine();

        string[] numbers = Console.ReadLine()
            .Split(new []{' '}, StringSplitOptions.RemoveEmptyEntries);

        bool stuckNumbersFound = false;

        for (int i = 0; i < numbers.Length; i++)
        {
            for (int j = 0; j < numbers.Length; j++)
            {
                if (j == i)
                {
                    continue;
                }

                for (int k = 0; k < numbers.Length; k++)
                {
                    if (k == i || k == j)
                    {
                        continue;
                    }

                    for (int l = 0; l < numbers.Length; l++)
                    {
                        if (l == k || l == j || l == i)
                        {
                            continue;
                        }

                        string leftside = numbers[i] + numbers[j];
                        string rightside = numbers[k] + numbers[l];

                        if (leftside == rightside)
                        {
                            Console.WriteLine(
                                "{0}|{1}=={2}|{3}",
                                numbers[i],
                                numbers[j],
                                numbers[k],
                                numbers[l]);

                            stuckNumbersFound = true;
                        }
                    }
                }
            }
        }

        if (!stuckNumbersFound)
        {
            Console.WriteLine("No");
        }
    }
}