bbb bbd bbk bbo bbs bbt bdb bdd bdk bdo bds bdt bkb bkk bko bks bkt bob bod bok boo bos bot bsb bsd bsk bso bss bst btb btd btk bto bts btt dbb dbd dbk dbo dbs dbt ddb ddd ddk ddo dds ddt dkb dkk dko dks dkt dob dod dok doo dos dot dsb dsd dsk dso dss dst dtb dtd dtk dto dts dtt k-t kbb kbd kbk kbo kbs kdb kdk kdo kds kdt kkb kkk kks kkt kob kod kok koo kos kot ksb ksd ksk kso kss kst ktb ktk kto kts ktt ob- obb obd obk obo obs obt odb odd odo ods odt okb okd okk oko oks oo- oob ood ook ooo oos oot os- osb osd osk oso oss ost ot- otb otd otk oto ots ott sbb sbd sbk sbo sbs sbt sdb sdd sdk sdo sds sdt sk- skb skd skk sko sks skt sob sod sok soo sos sot ss- ssb ssd ssk sso sss sst stb std stk sto sts stt tbb tbd tbk tbo tbs tbt tdb tdd tdk tdo tds tdt tkb tkk tko tks tkt to- tob tod tok too tos tot tsb tsd tsk tso tss tst ttb ttd ttk tto tts ttt