private void Box40_TextChanged(object sender, EventArgs e)
{
int[,] arr = mapTableToArray(); CCC = new CheckCorrectCell(arr);
if (CCC.checkCorrectCell9x9(4, 3) &&
Box40.Text != "")
{
Box40.BackColor = Color.Red;
}
else
Box40.BackColor = Color.White;
congratulations9x9();
}