you may have multiple lines
string[] rows = TextBox1.Text.Split (new string[]{System.Environment.NewLine}, StringSplitOptions.None );
string[] row1 = rows[1].Split();
var rowA = int.Parse(row1[1]) +int.Parse(row1[3]);
string[] row2 = rows[2].Split();
var rowB = int.Parse(row2[2]) +int.Parse(row2[3]);