bbb bbd bbk bbn bbo bbr bdb bdd bdk bdo bdr bkb bkk bkn bko bkr bnb bnd bnk bnn bno bnr bob bod bok bon boo bor brb brd brk brn bro brr dbb dbd dbk dbn dbo dbr ddb ddd ddk ddn ddo ddr dkb dkk dko dkr dnb dnd dnk dnn dno dnr dob dod dok don doo dor drb drd drk drn dro drr kbb kbd kbk kbn kbo kbr kdb kdk kdo kdr kkb kkk kkn kkr kn- knd knk knn kno knr kob kod kok kon koo kor krd krk krn kro krr nbb nbd nbk nbn nbo nbr ndb ndd ndk ndn ndo ndr nkk nkn nko nkr nnb nnk nnn nno no- nob nod nok non noo nor nrb nrd nrk nrn nro nrr ob- obb obd obk obn obo obr odb odd odn odo odr okb okd okk oko okr on- onb ond onk onn ono onr oo- oob ood ook oon ooo oor or- orb ord ork orn oro orr rbb rbd rbk rbn rbo rbr rdb rdd rdn rdo rdr rkb rkk rko rnb rnd rnn rno rnr rob rod rok ron roo ror rrb rrd rrk rrn rrr