bbb bbk bbn bbo bbs bbt bkb bkk bkn bko bks bkt bnb bnk bnn bno bns bnt bob bok bon boo bos bot bsb bsk bsn bso bss bst btb btk btn bto bts btt k-t kbb kbk kbn kbo kbs kkb kkk kkn kks kkt kn- knk knn kno knt kob kok kon koo kos kot ksb ksk ksn kso kss kst ktb ktk ktn kto kts ktt nbb nbk nbn nbo nbs nbt nkk nkn nko nks nkt nnb nnk nnn nno nns nnt no- nob nok non noo nos not nsb nsk nsn nso nss nst ntb ntk ntn nto nts ntt ob- obb obk obn obo obs obt okb okk oko oks on- onb onk onn ono ons ont oo- oob ook oon ooo oos oot os- osb osk osn oso oss ost ot- otb otk otn oto ots ott sbb sbk sbn sbo sbs sbt sk- skb skk sko sks skt snb snk snn sno sns snt sob sok son soo sos sot ss- ssb ssk ssn sso sss sst stb stk stn sto sts stt tbb tbk tbn tbo tbs tbt tkb tkk tko tks tkt tnb tnk tnn tno tns tnt to- tob tok ton too tos tot tsb tsk tsn tso tss tst ttb ttk ttn tto tts ttt