Diagonal Difference

using System;
using System.Linq;

namespace HomeWork
{
    class Program
    {
        static void Main()
        {
            int n = int.Parse(Console.ReadLine());
            var matrix = new double[n][];
            for (int rowsIndex = 0; rowsIndex < n; rowsIndex++)
            {
                var nums = Console.ReadLine().Split(' ').Select(double.Parse).ToArray();
                matrix[rowsIndex] = nums;
            }
            double diagonalSum1 = 0;
            for (int i = 0; i < n; i++)
                diagonalSum1 += matrix[i][i];

            double diagonalSum2 = 0;
            int start = n - 1;
            for (int i = 0; i < n; i++)
            {
                diagonalSum2 += matrix[i][start];
                start--;
            }
            Console.WriteLine(Math.Abs(diagonalSum1 - diagonalSum2));
        }
    }
}