-ic bbb bbc bbi bbk bbn bbo bbr bbs bcb bcc bci bck bcn bco bcr bcs bi- bib bic bii bik bin bio bir bis bkb bkc bkk bkn bko bkr bks bnb bnc bni bnk bnn bno bnr bns bob boc boi bok bon boo bor bos brb bri brk brn bro brr brs bsb bsc bsi bsk bsn bso bsr bss c-- cbb cbc cbi cbk cbn cbo cbr cbs ccb ccc cci cck ccn cco ccr ccs ci- cib cic cii cik cin cio cir cis ckb ckc cki cko cks cn- cnb cnc cni cnn cno cnr cns co- cob coc coi cok con coo cor cos crb crc cri crk crn cro crr crs csb csc csi csk csn cso csr css ibb ibc ibi ibk ibn ibo ibr ibs icb icc ici ick icn ico icr ics iib iic iii iin iio iir iis ikb ikc iki ikk iko ikr iks in- inb inc ini ink inn ino inr ins io- iob ioc ioi ion ioo ior ios ir- irb irc iri irk irn iro irr irs is- isb isc isi isk isn iso isr iss kbb kbc kbi kbk kbn kbo kbr kbs kcb kcc kci kck kcn kcr kcs kib kic kii kik kin kio kir kis kkb kkc kki kkk kkn kkr kks kn- knc kni knk knn kno knr kob koc koi kok kon koo kor kos krc kri krk krn kro krr krs ksb ksc ksi ksk ksn kso ksr kss n-i nbb nbc nbi nbk nbn nbo nbr nbs ncb ncc nci nck ncn nco ncr ncs nib nic nii nik nin nio nir nis nkc nki nkk nkn nko nkr nks nnb nnc nni nnk nnn nno nns no- nob noc noi nok non noo nor nos nrb nrc nri nrk nrn nro nrr nrs nsb nsc nsi nsk nsn nso nsr nss o-i ob- obb obc obi obk obn obo obr obs oc- ocb occ oci ock ocn oco ocr ocs oib oic oii oik oin oio oir ois okb okc oki okk oko okr oks on- onb onc oni onk onn ono onr ons oo- oob ooc ooi ook oon ooo oor oos or- orb orc ori ork orn oro orr ors os- osb osc osi osk osn oso osr oss rbb rbc rbi rbk rbn rbo rbr rbs rcb rcc rci rcn rco rcr rcs rib ric rii rik rin rio rir ris rkb rkc rkk rko rks rnb rnc rni rnn rno rnr rns rob roc roi rok ron roo ror ros rrb rrc rri rrk rrn rrr rrs rsb rsc rsi rsk rsn rso rsr rss sbb sbc sbi sbk sbn sbo sbr sbs scb scc sci sck scn sco scr scs sib sic sii sik sin sio sir sis sk- skb skc ski skk sko skr sks snb snc sni snk snn sno snr sns sob soc soi sok son soo sor sos sr- srb src sri srk srn sro srr srs ss- ssb ssc ssi ssk ssn sso ssr sss