KnightGame

using System;
using System.Collections.Generic;
using System.Linq;

namespace KnightGame
{
    public class StartUp
    {
        public static void Main()
        {
            int boardSize = int.Parse(Console.ReadLine());
            char[,] board = new char[boardSize, boardSize];
            var indexes = new Dictionary<List<int>, int>();
            int removeCounter = 0;
            for (int i = 0; i < board.GetLength(0); i++)
            {
                char[] rows = Console.ReadLine().ToCharArray();
                for (int j = 0; j < board.GetLength(1); j++)
                {
                    board[i, j] = rows[j];
                }
            }
            while (true)
            {
                SetIndexes(indexes, board);
                if (indexes.Values.Any(x => x != 0))
                {
                    RemoveKnight(indexes, board);
                    removeCounter++;
                    indexes.Clear();
                }
                else
                {
                    break;
                }
            }
            Console.WriteLine(removeCounter);
        }

        private static void RemoveKnight(Dictionary<List<int>, int> indexes, char[,] board)
        {
            int max = indexes.Values.Max();
            var coordinatesForRemoval = indexes.FirstOrDefault(x => x.Value == max).Key;
            board[coordinatesForRemoval[0], coordinatesForRemoval[1]] = '0';
        }

        private static void SetIndexes(Dictionary<List<int>, int> indexes, char[,] board)
        {
            int counter = 0;
            for (int i = 0; i < board.GetLength(0); i++)
            {
                for (int j = 0; j < board.GetLength(1); j++)
                {
                    if (board[i, j] == 'K')
                    {
                        int[] coordinates = { i, j };
                        counter = CountKnights(board, i, j, board.GetLength(0));
                        indexes.Add(new List<int>(coordinates), counter);
                    }
                }
            }
        }

        private static int CountKnights(char[,] board, int i, int j, int length)
        {
            bool isThereAKnight = false;
            int counter = 0;
            if (i + 2 < length && j + 1 < length)
            {
                isThereAKnight = CheckForKnight(board[i + 2, j + 1]);
                counter = SetCounter(isThereAKnight, counter);
            }
            if (i + 2 < length && j - 1 >= 0)
            {
                isThereAKnight = CheckForKnight(board[i + 2, j - 1]);
                counter = SetCounter(isThereAKnight, counter);
            }
            if (i - 2 >= 0 && j + 1 < length)
            {
                isThereAKnight = CheckForKnight(board[i - 2, j + 1]);
                counter = SetCounter(isThereAKnight, counter);
            }
            if (i - 2 >= 0 && j - 1 >= 0)
            {
                isThereAKnight = CheckForKnight(board[i - 2, j - 1]);
                counter = SetCounter(isThereAKnight, counter);
            }
            if (j + 2 < length && i + 1 < length)
            {
                isThereAKnight = CheckForKnight(board[i + 1, j + 2]);
                counter = SetCounter(isThereAKnight, counter);
            }
            if (j + 2 < length && i - 1 >= 0)
            {
                isThereAKnight = CheckForKnight(board[i - 1, j + 2]);
                counter = SetCounter(isThereAKnight, counter);
            }
            if (j - 2 >= 0 && i + 1 < length)
            {
                isThereAKnight = CheckForKnight(board[i + 1, j - 2]);
                counter = SetCounter(isThereAKnight, counter);
            }
            if (j - 2 >= 0 && i - 1 >= 0)
            {
                isThereAKnight = CheckForKnight(board[i - 1, j - 2]);
                counter = SetCounter(isThereAKnight, counter);
            }
            return counter;
        }

        private static int SetCounter(bool isThereAKnight, int counter)
        {
            if (isThereAKnight)
            {
                counter++;
            }

            return counter;
        }

        private static bool CheckForKnight(char element)
        {
            if (element == 'K')
            {
                return true;
            }
            return false;
        }
    }
}