4


....B...
....B...
....B...
RRRRRRRR
....B...
....B...
....B...
....B...


RRRRRRRB
B......B
B......B
B......B
B......B
B......B
B......B
RRRRRRRB


RRRRRRBB
.B.B..BB
RRRRRRBB
.B.B..BB
.B.B..BB
RRRRRRBB
.B.B..BB
.B.B..BB


........
........
........
RRRRRRRR
........
........
........
........