Multidimensional Arrays - 1. Sum Matrix Elements

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 int[rows, cols];

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

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

            Console.WriteLine(matrix.GetLength(0));
            Console.WriteLine(matrix.GetLength(1));

            var sum = 0;

            foreach (var item in matrix)
            {
                sum += item;
            }

            Console.WriteLine(sum);
        }
    }
}