private void Box78_TextChanged(object sender, EventArgs e)
{
int[,] arr = mapTableToArray(); CCC = new CheckCorrectCell(arr);
if (CCC.checkCorrectCell9x9(8, 5) &&
Box78.Text != "")
{
Box78.BackColor = Color.Red;
}
else
Box78.BackColor = Color.White;
congratulations9x9();
}