-er -ic b-p bbb bbc bbe bbi bbk bbo bbp bbr bbs bbx bcb bcc bce bci bck bco bcp bcr bcs bcx be- beb bec bee bei bek beo bep ber bes bex bi- bib bic bie bii bik bio bip bir bis bix bkb bkc bke bkk bko bkp bkr bks bkx bob boc boe boi bok boo bop bor bos box bpb bpc bpe bpi bpo bpp bpr bps bpx brb bre bri brk bro brp brr brs brx bsb bsc bse bsi bsk bso bsp bsr bss bsx bxb bxi bxo bxx c-- cbb cbc cbe cbi cbk cbo cbp cbr cbs cbx ccb ccc cce cci cck cco ccp ccr ccs ccx ce- ceb cec cee cei cek ceo cep cer ces cex ci- cib cic cie cii cik cio cip cir cis cix ckb ckc cki cko cks ckx co- cob coc coe coi cok coo cop cor cos cox cpb cpc cpe cpi cpk cpo cpp cpr cps cpx crb crc cre cri crk cro crp crr crs crx csb csc cse csi csk cso csp csr css csx cxc cxi cxk cxo cxp cxr cxs cxx ebb ebc ebe ebi ebk ebo ebp ebr ebs ebx ec- ecb ecc ece eci eck eco ecr ecs ecx eeb eec eee eek eeo eep eer ees eex eib eic eie eii eik eio eip eir eis eix ekb ekc eke eki eko ekp ekr eks eo- eob eoc eoe eoi eok eoo eop eor eos ep- epb epc epe epi epo epp epr eps epx erb erc ere eri erk ero erp err ers es- esb esc ese esi esk eso esp esr ess esx ex- exc exe exi exo exp exr exs exx ibb ibc ibe ibi ibk ibo ibp ibr ibs ibx icb icc ice ici ick ico icp icr ics ie- iec iee iei iek iep ier ies iex iib iic iie iii iio iip iir iis iix ikb ikc ike iki ikk iko ikr iks ikx io- iob ioc ioe ioi ioo iop ior ios ipb ipc ipe ipi ipo ipp ipr ips ipx ir- irb irc ire iri irk iro irp irr irs irx is- isb isc ise isi isk iso isp isr iss ixc ixe ixi kbb kbc kbe kbi kbk kbo kbp kbr kbs kbx kcb kcc kce kci kck kcp kcr kcs kcx ke- keb kec kee kei kek keo kep ker kes kex kib kic kie kii kik kio kip kir kis kix kkb kkc kke kki kkk kkp kkr kks kob koc koe koi kok koo kop kor kos kpc kpe kpi kpk kpo kpp kpr kps krc kri krk kro krp krr krs ksb ksc kse ksi ksk kso ksp ksr kss kxo o-i ob- obb obc obe obi obk obo obp obr obs obx oc- ocb occ oci ock oco ocp ocr ocs ocx oeb oec oee oei oeo oep oer oes oex oib oic oie oii oik oio oip oir ois okb okc oke oki okk oko okp okr oks oo- oob ooc ooi ook ooo oop oor oos oox op- opb opc ope opi opk opo opp opr ops opx or- orb orc ore ori ork oro orp orr ors orx os- osb osc ose osi osk oso osp osr oss osx ox- oxb oxc oxi oxo oxx p-p pbb pbc pbe pbi pbk pbo pbp pbr pbs pbx pcb pcc pce pci pck pco pcp pcr pcs pcx peb pec pee pei pek peo pep per pes pex pib pic pie pii pik pio pip pir pis pix pkb pkc pke pki pko pkp pkr pks pob poc poe poi pok poo pop por pos pox ppb ppc ppe ppi ppk ppo ppp ppr pps ppx prb prc pre pri prk pro prp prr prs prx ps- psb psc pse psi psk pso psp psr pss psx pxc pxe pxk pxr pxs rbb rbc rbe rbi rbk rbo rbp rbr rbs rbx rcb rcc rce rci rco rcp rcr rcs rcx re- reb rec ree rei rek reo rep rer res rex rib ric rie rii rik rio rip rir ris rix rkb rkc rke rkk rko rkp rks rob roc roe roi rok roo rop ror ros rox rpb rpc rpe rpi rpk rpo rpp rpr rps rpx rrb rrc rri rrk rrp rrr rrs rsb rsc rse rsi rsk rso rsp rsr rss rsx rxp rxr rxs sbb sbc sbe sbi sbk sbo sbp sbr sbs sbx scb scc sce sci sck sco scp scr scs scx se- seb sec see sei sek seo sep ser ses sex sib sic sie sii sik sio sip sir sis six sk- skb skc ske ski skk sko skp skr sks skx sob soc soe soi sok soo sop sor sos sox spb spc spe spi spk spo spp spr sps spx sr- srb src sre sri srk sro srp srr srs srx ss- ssb ssc sse ssi ssk sso ssp ssr sss ssx sxc sxi sxs xbc xbe xbr xbx xcb xci xcp xcr xcx xee xep xer xes xex xic xie xii xio xis xix xkb xke xks xoc xoi xok xoo xop xor xos xox xpb xpc xpe xpo xpp xps xrc xrx xsb xsc xsi xsp xss xxi xxo xxp xxx