-er a-a a-b a-c a-t aaa aab aac aae aak aap aar aat aax ab- aba abb abc abe abk abp abr abt abx ac- aca acb acc ace ack acp acr act acx aea aeb aec aee aek aep aer aet aex aka akb akc ake akk akp akr ap- apa apb apc ape apk app apr apt apx ar- ara arb arc are ark arp arr art arx at- ata atb atc ate atp atr att atx ax- axa axe axk axp axr axt axx b-p baa bab bac bae bak bap bar bat bax bba bbb bbc bbe bbk bbp bbr bbt bbx bca bcb bcc bce bck bcp bcr bct bcx be- bea beb bec bee bek bep ber bet bex bka bkb bkc bke bkk bkp bkr bkt bkx bpa bpb bpc bpe bpp bpr bpt bpx bra brb bre brk brp brr brt brx bta btb btc bte btk btp btr btt btx bxb bxx c-- caa cab cac cae cak cap car cat cax cba cbb cbc cbe cbk cbp cbr cbt cbx cca ccb ccc cce cck ccp ccr cct ccx ce- cea ceb cec cee cek cep cer cet cex cka ckb ckc ckt ckx cpa cpb cpc cpe cpk cpp cpr cpt cpx cra crb crc cre crk crp crr crt crx cta ctb ctc cte ctk ctp ctr ctt ctx cxc cxk cxp cxr cxt cxx eaa eab eac eae eak eap ear eat eax eba ebb ebc ebe ebk ebp ebr ebt ebx ec- eca ecb ecc ece eck ecr ect ecx eea eeb eec eee eek eep eer eet eex eka ekb ekc eke ekp ekr ekt ep- epa epb epc epe epp epr ept epx era erb erc ere erk erp err ert eta etb etc ete etk etp etr ett etx ex- exa exc exe exp exr ext exx k-t ka- kaa kab kac kae kak kap kar kat kax kba kbb kbc kbe kbk kbp kbr kbx kca kcb kcc kce kck kcp kcr kct kcx ke- kea keb kec kee kek kep ker ket kex kkb kkc kke kkk kkp kkr kkt kpa kpc kpe kpk kpp kpr kpt kra krc krk krp krr krt kta ktb ktc kte ktk ktp ktr ktt p-p paa pab pac pae pak pap par pat pax pba pbb pbc pbe pbk pbp pbr pbt pbx pca pcb pcc pce pck pcp pcr pct pcx pea peb pec pee pek pep per pet pex pka pkb pkc pke pkp pkr pkt ppa ppb ppc ppe ppk ppp ppr ppt ppx pra prb prc pre prk prp prr prt prx pt- pta ptb ptc pte ptk ptp ptr ptt ptx pxc pxe pxk pxr pxt ra- raa rab rac rae rak rap rar rat rax rba rbb rbc rbe rbk rbp rbr rbt rbx rca rcb rcc rce rcp rcr rct rcx re- rea reb rec ree rek rep rer ret rex rkb rkc rke rkk rkp rkt rpa rpb rpc rpe rpk rpp rpr rpt rpx rra rrb rrc rrk rrp rrr rrt rta rtb rtc rte rtk rtp rtr rtt rtx rxp rxr t-x taa tab tac tae tak tap tar tat tax tba tbb tbc tbe tbk tbp tbr tbt tca tcb tcc tce tck tcp tcr tct tcx te- tea teb tec tee tek tep ter tet tex tka tkb tkc tke tkk tkp tkr tkt tpa tpb tpc tpe tpk tpp tpr tpt tpx tra trb trc tre trk trp trr trt trx tta ttb ttc tte ttk ttp ttr ttt ttx txe txk txt xaa xac xak xap xar xat xbc xbe xbr xbx xcb xcp xcr xcx xee xep xer xet xex xkb xke xpa xpb xpc xpe xpp xpt xrc xrt xrx xtc xtp xtr xtx xxp xxx