20
ox........o....xo...
....o...o.....o.....
o.....xx.xox.....xox
....x...............
.x.....x.....o..x...
..x.x..........o..x.
o...o.....x.x..o....
........x...ox......
........o...........
....x..o........o...
............x......o
x..x..o..x....x.....
.......o............
....x.x....xo.oo....
...o.x..o.x..x...o..
.o...o.....o........
............xx....o.
.ox..x.oo.....ox....
........oxxo....o...
xo.....o.......x....
