-er a-a a-b a-c aaa aab aac aae aak aap aar aas aax ab- aba abb abc abe abk abp abr abs abx ac- aca acb acc ace ack acp acr acs acx aea aeb aec aee aek aep aer aes aex aka akb akc ake akk akp akr aks ap- apa apb apc ape apk app apr aps apx ar- ara arb arc are ark arp arr ars arx as- asa asb asc ase ask asp asr ass asx ax- axa axe axk axp axr axs axx b-p baa bab bac bae bak bap bar bas bax bba bbb bbc bbe bbk bbp bbr bbs bbx bca bcb bcc bce bck bcp bcr bcs bcx be- bea beb bec bee bek bep ber bes bex bka bkb bkc bke bkk bkp bkr bks bkx bpa bpb bpc bpe bpp bpr bps bpx bra brb bre brk brp brr brs brx bsa bsb bsc bse bsk bsp bsr bss bsx bxb bxx c-- caa cab cac cae cak cap car cas cax cba cbb cbc cbe cbk cbp cbr cbs cbx cca ccb ccc cce cck ccp ccr ccs ccx ce- cea ceb cec cee cek cep cer ces cex cka ckb ckc cks ckx cpa cpb cpc cpe cpk cpp cpr cps cpx cra crb crc cre crk crp crr crs crx csa csb csc cse csk csp csr css csx cxc cxk cxp cxr cxs cxx eaa eab eac eae eak eap ear eas eax eba ebb ebc ebe ebk ebp ebr ebs ebx ec- eca ecb ecc ece eck ecr ecs ecx eea eeb eec eee eek eep eer ees eex eka ekb ekc eke ekp ekr eks ep- epa epb epc epe epp epr eps epx era erb erc ere erk erp err ers es- esa esb esc ese esk esp esr ess esx ex- exa exc exe exp exr exs exx ka- kaa kab kac kae kak kap kar kas kax kba kbb kbc kbe kbk kbp kbr kbs kbx kca kcb kcc kce kck kcp kcr kcs kcx ke- kea keb kec kee kek kep ker kes kex kkb kkc kke kkk kkp kkr kks kpa kpc kpe kpk kpp kpr kps kra krc krk krp krr krs ksa ksb ksc kse ksk ksp ksr kss p-p paa pab pac pae pak pap par pas pax pba pbb pbc pbe pbk pbp pbr pbs pbx pca pcb pcc pce pck pcp pcr pcs pcx pea peb pec pee pek pep per pes pex pka pkb pkc pke pkp pkr pks ppa ppb ppc ppe ppk ppp ppr pps ppx pra prb prc pre prk prp prr prs prx ps- psa psb psc pse psk psp psr pss psx pxc pxe pxk pxr pxs ra- raa rab rac rae rak rap rar ras rax rba rbb rbc rbe rbk rbp rbr rbs rbx rca rcb rcc rce rcp rcr rcs rcx re- rea reb rec ree rek rep rer res rex rkb rkc rke rkk rkp rks rpa rpb rpc rpe rpk rpp rpr rps rpx rra rrb rrc rrk rrp rrr rrs rsa rsb rsc rse rsk rsp rsr rss rsx rxp rxr rxs saa sab sac sae sak sap sar sas sax sba sbb sbc sbe sbk sbp sbr sbs sbx sca scb scc sce sck scp scr scs scx se- sea seb sec see sek sep ser ses sex sk- ska skb skc ske skk skp skr sks skx spa spb spc spe spk spp spr sps spx sr- sra srb src sre srk srp srr srs srx ss- ssa ssb ssc sse ssk ssp ssr sss ssx sxc sxs xaa xac xak xap xar xas xbc xbe xbr xbx xcb xcp xcr xcx xee xep xer xes xex xkb xke xks xpa xpb xpc xpe xpp xps xrc xrx xsa xsb xsc xsp xss xxp xxx