8 solutions found:

bbccc
bbccc
bb...
aaaaa

bb...
bbccc
bbccc
aaaaa

aaaaa
bbccc
bbccc
bb...

aaaaa
bb...
bbccc
bbccc

cccbb
cccbb
...bb
aaaaa

...bb
cccbb
cccbb
aaaaa

aaaaa
cccbb
cccbb
...bb

aaaaa
...bb
cccbb
cccbb