-er a-a a-b a-t aaa aab aae aak aan aap aar aat ab- aba abb abe abk abn abp abr abt aea aeb aee aek aen aep aer aet aka akb ake akk akn akp akr an- ana anb ane ank ann anp anr ant ap- apa apb ape apk apn app apr apt ar- ara arb are ark arn arp arr art at- ata atb ate atn atp atr att b-p baa bab bae bak ban bap bar bat bba bbb bbe bbk bbn bbp bbr bbt be- bea beb bee bek ben bep ber bet bka bkb bke bkk bkn bkp bkr bkt bna bnb bne bnk bnn bnp bnr bnt bpa bpb bpe bpn bpp bpr bpt bra brb bre brk brn brp brr brt bta btb bte btk btn btp btr btt eaa eab eae eak ean eap ear eat eba ebb ebe ebk ebn ebp ebr ebt eea eeb eee eek een eep eer eet eka ekb eke ekp ekr ekt en- ena enb ene enk enn enp enr ent ep- epa epb epe epn epp epr ept era erb ere erk ern erp err ert eta etb ete etk etn etp etr ett k-t ka- kaa kab kae kak kan kap kar kat kba kbb kbe kbk kbn kbp kbr ke- kea keb kee kek ken kep ker ket kkb kke kkk kkn kkp kkr kkt kn- kna kne knk knn knp knr knt kpa kpe kpk kpn kpp kpr kpt kra krk krn krp krr krt kta ktb kte ktk ktn ktp ktr ktt naa nab nae nak nan nap nar nat nba nbb nbe nbk nbn nbp nbr nbt ne- nea neb nee nek nen nep ner net nka nke nkk nkn nkp nkr nkt nna nnb nne nnk nnn nnp nnt npa npb npe npn npp npr npt nra nrb nre nrk nrn nrp nrr nrt nta ntb nte ntk ntn ntp ntr ntt p-p paa pab pae pak pan pap par pat pba pbb pbe pbk pbn pbp pbr pbt pea peb pee pek pen pep per pet pka pkb pke pkn pkp pkr pkt pn- pna pnb pne pnk pnn pnp pnr pnt ppa ppb ppe ppk ppn ppp ppr ppt pra prb pre prk prn prp prr prt pt- pta ptb pte ptk ptn ptp ptr ptt ra- raa rab rae rak ran rap rar rat rba rbb rbe rbk rbn rbp rbr rbt re- rea reb ree rek ren rep rer ret rkb rke rkk rkp rkt rna rnb rnn rnp rnr rnt rpa rpb rpe rpk rpn rpp rpr rpt rra rrb rrk rrn rrp rrr rrt rta rtb rte rtk rtn rtp rtr rtt taa tab tae tak tan tap tar tat tba tbb tbe tbk tbn tbp tbr tbt te- tea teb tee tek ten tep ter tet tka tkb tke tkk tkp tkr tkt tna tnb tne tnk tnn tnp tnr tnt tpa tpb tpe tpk tpn tpp tpr tpt tra trb tre trk trn trp trr trt tta ttb tte ttk ttn ttp ttr ttt