-er a-a a-b a-t aaa aab aad aae aak aar aas aat ab- aba abb abd abe abk abr abs abt ad- ada adb add ade adk adr ads adt aea aeb aed aee aek aer aes aet aka akb akd ake akk akr aks ar- ara arb ard are ark arr ars art as- asa asb asd ase ask asr ass ast at- ata atb atd ate atr ats att baa bab bad bae bak bar bas bat bba bbb bbd bbe bbk bbr bbs bbt bda bdb bdd bde bdk bdr bds bdt be- bea beb bed bee bek ber bes bet bka bkb bke bkk bkr bks bkt bra brb brd bre brk brr brs brt bsa bsb bsd bse bsk bsr bss bst bta btb btd bte btk btr bts btt daa dab dad dae dak dar das dat dba dbb dbd dbe dbk dbr dbs dbt dda ddb ddd dde ddk ddr dds ddt de- dea deb ded dee dek der des det dka dkb dke dkk dkr dks dkt dra drb drd dre drk drr drs drt dsa dsb dsd dse dsk dsr dss dst dta dtb dtd dte dtk dtr dts dtt eaa eab ead eae eak ear eas eat eba ebb ebd ebe ebk ebr ebs ebt ed- eda edb edd ede edk edr eds edt eea eeb eed eee eek eer ees eet eka ekb ekd eke ekr eks ekt era erb erd ere erk err ers ert es- esa esb esd ese esk esr ess est eta etb etd ete etk etr ets ett k-t ka- kaa kab kad kae kak kar kas kat kba kbb kbd kbe kbk kbr kbs kda kdb kde kdk kdr kds kdt ke- kea keb ked kee kek ker kes ket kkb kke kkk kkr kks kkt kra krd krk krr krs krt ksa ksb ksd kse ksk ksr kss kst kta ktb kte ktk ktr kts ktt ra- raa rab rad rae rak rar ras rat rba rbb rbd rbe rbk rbr rbs rbt rda rdb rdd rde rdr rds rdt re- rea reb red ree rek rer res ret rkb rke rkk rks rkt rra rrb rrd rrk rrr rrs rrt rsa rsb rsd rse rsk rsr rss rst rta rtb rtd rte rtk rtr rts rtt saa sab sad sae sak sar sas sat sba sbb sbd sbe sbk sbr sbs sbt sda sdb sdd sde sdk sdr sds sdt se- sea seb sed see sek ser ses set sk- ska skb skd ske skk skr sks skt sr- sra srb srd sre srk srr srs srt ss- ssa ssb ssd sse ssk ssr sss sst sta stb std ste stk str sts stt taa tab tad tae tak tar tas tat tba tbb tbd tbe tbk tbr tbs tbt tda tdb tdd tde tdk tdr tds tdt te- tea teb ted tee tek ter tes tet tka tkb tke tkk tkr tks tkt tra trb trd tre trk trr trs trt tsa tsb tsd tse tsk tsr tss tst tta ttb ttd tte ttk ttr tts ttt