-er a-a a-b a-c a-t aaa aab aac aae aaf aak aap aar aat ab- aba abb abc abe abf abk abp abr abt ac- aca acb acc ace acf ack acp acr act aea aeb aec aee aef aek aep aer aet af- afa afb afc afe aff afk afp afr aft aka akb akc ake akk akp akr ap- apa apb apc ape apf apk app apr apt ar- ara arb arc are arf ark arp arr art at- ata atb atc ate atf atp atr att b-p baa bab bac bae baf bak bap bar bat bba bbb bbc bbe bbf bbk bbp bbr bbt bca bcb bcc bce bcf bck bcp bcr bct be- bea beb bec bee bef bek bep ber bet bfa bfb bfc bfe bff bfp bfr bft bka bkb bkc bke bkf bkk bkp bkr bkt bpa bpb bpc bpe bpf bpp bpr bpt bra brb bre brf brk brp brr brt bta btb btc bte btf btk btp btr btt c-- caa cab cac cae caf cak cap car cat cba cbb cbc cbe cbf cbk cbp cbr cbt cca ccb ccc cce ccf cck ccp ccr cct ce- cea ceb cec cee cef cek cep cer cet cfa cfb cfc cfe cff cfk cfp cfr cft cka ckb ckc ckt cpa cpb cpc cpe cpf cpk cpp cpr cpt cra crb crc cre crf crk crp crr crt cta ctb ctc cte ctf ctk ctp ctr ctt eaa eab eac eae eaf eak eap ear eat eba ebb ebc ebe ebf ebk ebp ebr ebt ec- eca ecb ecc ece ecf eck ecr ect eea eeb eec eee eef eek eep eer eet ef- efa efb efc efe eff efp efr eft eka ekb ekc eke ekf ekp ekr ekt ep- epa epb epc epe epf epp epr ept era erb erc ere erf erk erp err ert eta etb etc ete etf etk etp etr ett faa fab fac fae faf fak fap far fat fba fbb fbc fbe fbf fbk fbp fbr fbt fca fcb fcc fce fcf fck fcp fcr fct fea feb fec fee fef fek fep fer fet ffa ffc ffe fff ffk ffp ffr fft fka fkb fkc fkf fkk fkp fkt fpa fpb fpc fpe fpk fpp fpr fpt fra frb frc fre frf frk frp frr frt fta ftb ftc fte ftf ftk ftp ftr ftt k-t ka- kaa kab kac kae kaf kak kap kar kat kba kbb kbc kbe kbf kbk kbp kbr kca kcb kcc kce kck kcp kcr kct ke- kea keb kec kee kef kek kep ker ket kfa kfc kff kkb kkc kke kkk kkp kkr kkt kpa kpc kpe kpf kpk kpp kpr kpt kra krc krf krk krp krr krt kta ktb ktc kte ktf ktk ktp ktr ktt p-p paa pab pac pae paf pak pap par pat pba pbb pbc pbe pbf pbk pbp pbr pbt pca pcb pcc pce pcf pck pcp pcr pct pea peb pec pee pef pek pep per pet pfa pfb pfc pfe pff pfk pfp pfr pft pka pkb pkc pke pkf pkp pkr pkt ppa ppb ppc ppe ppf ppk ppp ppr ppt pra prb prc pre prf prk prp prr prt pt- pta ptb ptc pte ptf ptk ptp ptr ptt ra- raa rab rac rae raf rak rap rar rat rba rbb rbc rbe rbf rbk rbp rbr rbt rca rcb rcc rce rcf rcp rcr rct re- rea reb rec ree ref rek rep rer ret rfa rfb rfc rfe rff rfk rfp rfr rft rkb rkc rke rkf rkk rkp rkt rpa rpb rpc rpe rpf rpk rpp rpr rpt rra rrb rrc rrf rrk rrp rrr rrt rta rtb rtc rte rtf rtk rtp rtr rtt taa tab tac tae taf tak tap tar tat tba tbb tbc tbe tbf tbk tbp tbr tbt tca tcb tcc tce tcf tck tcp tcr tct te- tea teb tec tee tef tek tep ter tet tfa tfb tfc tfe tff tfk tfp tfr tft tka tkb tkc tke tkk tkp tkr tkt tpa tpb tpc tpe tpf tpk tpp tpr tpt tra trb trc tre trf trk trp trr trt tta ttb ttc tte ttf ttk ttp ttr ttt