10
.64..
.1...
.3...
52...
.....

2....
435..
..16.
.....
.....

...6.
4512.
3....
.....
.....

..2..
461..
..53.
.....
.....

.26..
35...
.1...
.4...
.....

46...
.25..
..31.
.....
.....

.5...
.31..
24...
6....
.....

..2..
.64..
.1...
53...
.....

.6...
514..
.3...
.2...
.....

.5...
.431.
62...
.....
.....