-ic bbb bbc bbd bbi bbk bbo bbr bbs bcb bcc bcd bci bck bco bcr bcs bdb bdc bdd bdi bdk bdo bdr bds bi- bib bic bid bii bik bio bir bis bkb bkc bkk bko bkr bks bob boc bod boi bok boo bor bos brb brd bri brk bro brr brs bsb bsc bsd bsi bsk bso bsr bss c-- cbb cbc cbd cbi cbk cbo cbr cbs ccb ccc ccd cci cck cco ccr ccs cdb cdc cdd cdi cdk cdo cdr cds ci- cib cic cid cii cik cio cir cis ckb ckc ckd cki cko cks co- cob coc cod coi cok coo cor cos crb crc crd cri crk cro crr crs csb csc csd csi csk cso csr css dbb dbc dbd dbi dbk dbo dbr dbs dcb dcc dcd dci dck dco dcr dcs ddb ddc ddd ddi ddk ddo ddr dds di- dib dic did dii dik dio dir dis dkb dkc dki dkk dko dkr dks dob doc dod doi dok doo dor dos drb drc drd dri drk dro drr drs dsb dsc dsd dsi dsk dso dsr dss i-d ibb ibc ibd ibi ibk ibo ibr ibs icb icc icd ici ick ico icr ics idb idc idd idi idk ido idr ids iib iic iid iii iio iir iis ikb ikc iki ikk iko ikr iks io- iob ioc iod ioi ioo ior ios ir- irb irc ird iri irk iro irr irs is- isb isc isd isi isk iso isr iss kbb kbc kbd kbi kbk kbo kbr kbs kcb kcc kcd kci kck kcr kcs kdb kdc kdk kdo kdr kds kib kic kid kii kik kio kir kis kkb kkc kki kkk kkr kks kob koc kod koi kok koo kor kos krc krd kri krk kro krr krs ksb ksc ksd ksi ksk kso ksr kss o-i ob- obb obc obd obi obk obo obr obs oc- ocb occ ocd oci ock oco ocr ocs odb odc odd odi odo odr ods oib oic oid oii oik oio oir ois okb okc okd oki okk oko okr oks oo- oob ooc ood ooi ook ooo oor oos or- orb orc ord ori ork oro orr ors os- osb osc osd osi osk oso osr oss rbb rbc rbd rbi rbk rbo rbr rbs rcb rcc rcd rci rco rcr rcs rdb rdc rdd rdi rdo rdr rds rib ric rid rii rik rio rir ris rkb rkc rkk rko rks rob roc rod roi rok roo ror ros rrb rrc rrd rri rrk rrr rrs rsb rsc rsd rsi rsk rso rsr rss sbb sbc sbd sbi sbk sbo sbr sbs scb scc scd sci sck sco scr scs sdb sdc sdd sdi sdk sdo sdr sds sib sic sid sii sik sio sir sis sk- skb skc skd ski skk sko skr sks sob soc sod soi sok soo sor sos sr- srb src srd sri srk sro srr srs ss- ssb ssc ssd ssi ssk sso ssr sss