public static int diagonalDifference(List<List<int>> arr)
    {
        int sizeCol = arr[0].Count;
        int diagonal1 = 0;
        int diagonal2 = 0;
        for(int i = 0; i<arr.Count; i++){
            for(int j = 0; j<sizeCol; j++){
                if(arr[i][j] < - 100 || arr[i][j] > 100) 
                    throw new Exception("Numero invalido");
                    
                if(i == j) diagonal1 += arr[i][j];
            }
            diagonal2 += arr[i][sizeCol - i - 1];
        }
        return Math.Abs(diagonal1 - diagonal2);
    }