#### Жишээ тэстүүд

##### Оролт
6
000000
000000
012100
024200
012100
000000

##### Гаралт
Yes


## Тэмдэглэл

The lair, if it exists, has to be rectangular (that is, have corners at some grid points with coordinates (x1, y1), (x1, y2), (x2, y1), (x2, y2)), has a non-zero area and be contained inside of the grid (that is, 0 ≤ x1 < x2 ≤ N, 0 ≤ y1 < y2 ≤ N), and result in the levels of Zombie Contamination as reported in the input.