-er b-p bbb bbc bbe bbn bbo bbp bbr bbs bbx bcb bcc bce bcn bco bcp bcr bcs bcx be- beb bec bee ben beo bep ber bes bex bnb bnc bne bnn bno bnp bnr bns bnx bob boc boe bon boo bop bor bos box bpb bpc bpe bpn bpo bpp bpr bps bpx brb bre brn bro brp brr brs brx bsb bsc bse bsn bso bsp bsr bss bsx bxb bxn bxo bxx c-- cbb cbc cbe cbn cbo cbp cbr cbs cbx ccb ccc cce ccn cco ccp ccr ccs ccx ce- ceb cec cee cen ceo cep cer ces cex cn- cnb cnc cne cnn cno cnp cnr cns cnx co- cob coc coe con coo cop cor cos cox cpb cpc cpe cpn cpo cpp cpr cps cpx crb crc cre crn cro crp crr crs crx csb csc cse csn cso csp csr css csx cxc cxo cxp cxr cxs cxx ebb ebc ebe ebn ebo ebp ebr ebs ebx ec- ecb ecc ece ecn eco ecr ecs ecx eeb eec eee een eeo eep eer ees eex en- enb enc ene enn eno enp enr ens eo- eob eoc eoe eon eoo eop eor eos ep- epb epc epe epn epo epp epr eps epx erb erc ere ern ero erp err ers es- esb esc ese esn eso esp esr ess esx ex- exc exe exo exp exr exs exx nbb nbc nbe nbn nbo nbp nbr nbs nbx ncb ncc nce ncn nco ncp ncr ncs ncx ne- neb nec nee nen neo nep ner nes nex nnb nnc nne nnn nno nnp nns no- nob noc noe non noo nop nor nos nox npb npc npe npn npo npp npr nps nrb nrc nre nrn nro nrp nrr nrs nrx nsb nsc nse nsn nso nsp nsr nss nsx nxc ob- obb obc obe obn obo obp obr obs obx oc- ocb occ ocn oco ocp ocr ocs ocx oeb oec oee oen oeo oep oer oes oex on- onb onc one onn ono onp onr ons onx oo- oob ooc oon ooo oop oor oos oox op- opb opc ope opn opo opp opr ops opx or- orb orc ore orn oro orp orr ors orx os- osb osc ose osn oso osp osr oss osx ox- oxb oxc oxn oxo oxx p-p pbb pbc pbe pbn pbo pbp pbr pbs pbx pcb pcc pce pcn pco pcp pcr pcs pcx peb pec pee pen peo pep per pes pex pn- pnb pnc pne pnn pno pnp pnr pns pnx pob poc poe pon poo pop por pos pox ppb ppc ppe ppn ppo ppp ppr pps ppx prb prc pre prn pro prp prr prs prx ps- psb psc pse psn pso psp psr pss psx pxc pxe pxr pxs rbb rbc rbe rbn rbo rbp rbr rbs rbx rcb rcc rce rcn rco rcp rcr rcs rcx re- reb rec ree ren reo rep rer res rex rnb rnc rnn rno rnp rnr rns rob roc roe ron roo rop ror ros rox rpb rpc rpe rpn rpo rpp rpr rps rpx rrb rrc rrn rrp rrr rrs rsb rsc rse rsn rso rsp rsr rss rsx rxp rxr rxs sbb sbc sbe sbn sbo sbp sbr sbs sbx scb scc sce scn sco scp scr scs scx se- seb sec see sen seo sep ser ses sex snb snc sne snn sno snp snr sns sob soc soe son soo sop sor sos sox spb spc spe spn spo spp spr sps spx sr- srb src sre srn sro srp srr srs srx ss- ssb ssc sse ssn sso ssp ssr sss ssx sxc sxn sxs xbc xbe xbr xbx xcb xcp xcr xcx xee xen xep xer xes xex xnc xno xns xoc xon xoo xop xor xos xox xpb xpc xpe xpn xpo xpp xps xrc xrx xsb xsc xsp xss xxo xxp xxx