-er -ic a-a a-b a-c a-i a-t aaa aab aac aae aai aak aar aas aat ab- aba abb abc abe abi abk abr abs abt ac- aca acb acc ace aci ack acr acs act aea aeb aec aee aei aek aer aes aet ai- aia aib aic aie aii aik air ais ait aka akb akc ake aki akk akr aks ar- ara arb arc are ari ark arr ars art as- asa asb asc ase asi ask asr ass ast at- ata atb atc ate ati atr ats att baa bab bac bae bai bak bar bas bat bba bbb bbc bbe bbi bbk bbr bbs bbt bca bcb bcc bce bci bck bcr bcs bct be- bea beb bec bee bei bek ber bes bet bi- bia bib bic bie bii bik bir bis bit bka bkb bkc bke bkk bkr bks bkt bra brb bre bri brk brr brs brt bsa bsb bsc bse bsi bsk bsr bss bst bta btb btc bte bti btk btr bts btt c-- caa cab cac cae cai cak car cas cat cba cbb cbc cbe cbi cbk cbr cbs cbt cca ccb ccc cce cci cck ccr ccs cct ce- cea ceb cec cee cei cek cer ces cet ci- cia cib cic cie cii cik cir cis cit cka ckb ckc cki cks ckt cra crb crc cre cri crk crr crs crt csa csb csc cse csi csk csr css cst cta ctb ctc cte cti ctk ctr cts ctt eaa eab eac eae eai eak ear eas eat eba ebb ebc ebe ebi ebk ebr ebs ebt ec- eca ecb ecc ece eci eck ecr ecs ect eea eeb eec eee eek eer ees eet eia eib eic eie eii eik eir eis eit eka ekb ekc eke eki ekr eks ekt era erb erc ere eri erk err ers ert es- esa esb esc ese esi esk esr ess est eta etb etc ete eti etk etr ets ett ia- iaa iab iac iae iai iar ias iat iba ibb ibc ibe ibi ibk ibr ibs ibt ica icb icc ice ici ick icr ics ict ie- iea iec iee iei iek ier ies iet iia iib iic iie iii iir iis iit ika ikb ikc ike iki ikk ikr iks ikt ir- ira irb irc ire iri irk irr irs irt is- isa isb isc ise isi isk isr iss ist ita itb itc ite iti itk its itt k-t ka- kaa kab kac kae kai kak kar kas kat kba kbb kbc kbe kbi kbk kbr kbs kca kcb kcc kce kci kck kcr kcs kct ke- kea keb kec kee kei kek ker kes ket kia kib kic kie kii kik kir kis kit kkb kkc kke kki kkk kkr kks kkt kra krc kri krk krr krs krt ksa ksb ksc kse ksi ksk ksr kss kst kta ktb ktc kte ktk ktr kts ktt ra- raa rab rac rae rai rak rar ras rat rba rbb rbc rbe rbi rbk rbr rbs rbt rca rcb rcc rce rci rcr rcs rct re- rea reb rec ree rei rek rer res ret ria rib ric rie rii rik rir ris rit rkb rkc rke rkk rks rkt rra rrb rrc rri rrk rrr rrs rrt rsa rsb rsc rse rsi rsk rsr rss rst rta rtb rtc rte rti rtk rtr rts rtt saa sab sac sae sai sak sar sas sat sba sbb sbc sbe sbi sbk sbr sbs sbt sca scb scc sce sci sck scr scs sct se- sea seb sec see sei sek ser ses set sia sib sic sie sii sik sir sis sit sk- ska skb skc ske ski skk skr sks skt sr- sra srb src sre sri srk srr srs srt ss- ssa ssb ssc sse ssi ssk ssr sss sst sta stb stc ste sti stk str sts stt taa tab tac tae tai tak tar tas tat tba tbb tbc tbe tbi tbk tbr tbs tbt tca tcb tcc tce tci tck tcr tcs tct te- tea teb tec tee tei tek ter tes tet tia tib tic tie tii tik tir tis tit tka tkb tkc tke tkk tkr tks tkt tra trb trc tre tri trk trr trs trt tsa tsb tsc tse tsi tsk tsr tss tst tta ttb ttc tte tti ttk ttr tts ttt