lonestSequence

using System;

class NeighborElements
{
    static int colCount;
    static int rolCount;
    static int lonestSequenceCounter = 0;
    static string lonestSequenceStr = " ";
    static string[,] array;
    static bool[,] arrayCheck;

    static void GetLongestSequence(int counter, int rol, int col)
    {
        if (counter > lonestSequenceCounter)
        {
            lonestSequenceCounter = counter;
            lonestSequenceStr = array[rol, col];
        }
    }

    static void MoveRight(int rol, int col, int count)
    {
        if (col >= colCount || rol >= rolCount) return;
        if (array[rol, col] == array[rol, col - 1])
        {
            ++count;
            GetLongestSequence(count, rol, col);
            MoveRight(rol, col + 1, count);
        }
        else
        {
            return;
        }
    }

    static void MoveCorner(int rol, int col, int count)
    {
        if (col >= colCount || rol >= rolCount) return;
        if (array[rol, col] == array[rol - 1, col - 1])
        {
            ++count;
            GetLongestSequence(count, rol, col);
            MoveCorner(rol + 1, col + 1, count);
        }
        else
        {
            return;
        }
    }

    static void MoveDown(int rol, int col, int count)
    {
        if (col >= colCount || rol >= rolCount) return;

        if (array[rol, col] == array[rol - 1, col])
        {
            ++count;
            GetLongestSequence(count, rol, col);
            MoveDown(rol + 1, col, count);
        }
        else
        {
            return;
        }
    }

    static void Main()
    {
        rolCount = int.Parse(Console.ReadLine());
        colCount = int.Parse(Console.ReadLine());
        array = new string[rolCount, colCount];

        // Input data in array
        for (int rol = 0; rol < rolCount; rol++)
        {
            string element = Console.ReadLine();
            string[] dontUse = new string[] { " " };
            string[] elementArray = element.Split(dontUse, StringSplitOptions.RemoveEmptyEntries);

            for (int col = 0; col < elementArray.Length; col++)
            {
                array[rol, col] = elementArray[col];
            }
        }

        // Solution
        for (int rol = 0; rol < rolCount; rol++)
        {
            for (int col = 0; col < colCount; col++)
            {
                MoveRight(rol, col + 1, 1);
                MoveCorner(rol + 1, col + 1, 1);
                MoveDown(rol + 1, col, 1);
            }
        }

        for (int i = 0; i < lonestSequenceCounter; i++)
        {
            Console.Write(lonestSequenceStr + " ");
        }
    }
}