Multidimensional Arrays - 02. Squares in Matrix

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

namespace Advanced
{
    class Program
    {
        static void Main(string[] args)
        {
            var dimentions = Console.ReadLine()
                .Split(new[] { ' '}, StringSplitOptions.RemoveEmptyEntries)
                .Select(int.Parse)
                .ToArray();

            int rows = dimentions[0];
            int cols = dimentions[1];

            var matrix = new char[rows, cols];

            for (int row = 0; row < rows; row++)
            {
                var currentRow = Console.ReadLine()
                .Split(new[] {' '}, StringSplitOptions.RemoveEmptyEntries)
                .Select(char.Parse)
                .ToArray();

                for (int col = 0; col < cols; col++)
                {
                    matrix[row, col] = currentRow[col];
                }
            }

            int counter = 0;

            for (int row = 0; row < matrix.GetLength(0) - 1; row++)
            {
                for (int col = 0; col < matrix.GetLength(1) - 1; col++)
                {
                    if (matrix[row, col] == matrix[row, col + 1] && matrix[row, col] == matrix[row + 1, col] && matrix[row, col] == matrix[row + 1, col + 1])
                    {
                        counter++;
                    }
                }
            }
            Console.WriteLine(counter);
        }
    }
}