public override string ToString()
{
string s = "";
for (int i = 0; i < Rows.Count; i++)
{
for (int j = 0; j < Rows[i].Length; j++)
{
if (!Rows[i].Any(x => x.IsEmpty()))
s += Rows[i][j].ToString() + (j == Rows[i].Length - 1 ? "\n" : " ");
}
}
return s;
}