Exam July Evening 4. Nakovs Matching

using System;
using System.Globalization;
using System.Threading;

public class NakovsMatching
{
    public static void Main()
    {
        Thread.CurrentThread.CurrentCulture = CultureInfo.InvariantCulture;
        checked
        {
            string wordFirst = Console.ReadLine();
            string wordSecond = Console.ReadLine();
            int distance = int.Parse(Console.ReadLine());

            bool foundMatchings = false;
            int firstSumLeft = 0;
            string firstLeftStr = string.Empty;
            for (int i = 0; i < wordFirst.Length - 1; i++)
            {
                firstLeftStr += wordFirst[i].ToString();
                firstSumLeft += wordFirst[i];
                int firstSumRight = 0;
                string firstRightStr = string.Empty;
                for (int j = i + 1; j < wordFirst.Length; j++)
                {
                    firstRightStr += wordFirst[j].ToString();
                    firstSumRight += wordFirst[j];
                }

                int secondSumLeft = 0;
                string secondLeftStr = string.Empty;
                for (int k = 0; k < wordSecond.Length - 1; k++)
                {
                    secondLeftStr += wordSecond[k].ToString();
                    secondSumLeft += wordSecond[k];
                    int secondSumRight = 0;
                    string secondRightStr = string.Empty;
                    for (int l = k + 1; l < wordSecond.Length; l++)
                    {
                        secondRightStr += wordSecond[l].ToString();
                        secondSumRight += wordSecond[l];
                    }

                    int result = Math.Abs((firstSumLeft * secondSumRight) - (firstSumRight * secondSumLeft));
                    if (result <= distance)
                    {
                        foundMatchings = true;
                        Console.WriteLine("({0}|{1}) matches ({2}|{3}) by {4} nakovs", firstLeftStr, firstRightStr, secondLeftStr, secondRightStr, result);
                    }
                }
            }

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