The first line contains a single integer $n$~--- the side length of the canvas ($1 \le n \le 1000$).

The next $n$ lines describe the canvas from top to bottom. The $i$-th of these lines contains $n$ characters $s_{i, 1}, s_{i, 2}, \ldots, s_{i, n}$. If $s_{i, j} =$ `\t{.}', the cell in the $i$-th row and the $j$-th column of the canvas is painted white. If $s_{i, j} =$ `\t{\#}', that cell is painted black. If $s_{i, j} =$ `\t{?}', that cell is empty.