-ic a-a a-b a-c a-i a-t aaa aab aac aai aak aar aas aat ab- aba abb abc abi abk abr abs abt ac- aca acb acc aci ack acr acs act ai- aia aib aic aii aik air ais ait aka akb akc aki akk akr aks ar- ara arb arc ari ark arr ars art as- asa asb asc asi ask asr ass ast at- ata atb atc ati atr ats att baa bab bac bai bak bar bas bat bba bbb bbc bbi bbk bbr bbs bbt bca bcb bcc bci bck bcr bcs bct bi- bia bib bic bii bik bir bis bit bka bkb bkc bkk bkr bks bkt bra brb bri brk brr brs brt bsa bsb bsc bsi bsk bsr bss bst bta btb btc bti btk btr bts btt c-- caa cab cac cai cak car cas cat cba cbb cbc cbi cbk cbr cbs cbt cca ccb ccc cci cck ccr ccs cct ci- cia cib cic cii cik cir cis cit cka ckb ckc cki cks ckt cra crb crc cri crk crr crs crt csa csb csc csi csk csr css cst cta ctb ctc cti ctk ctr cts ctt ia- iaa iab iac iai iar ias iat iba ibb ibc ibi ibk ibr ibs ibt ica icb icc ici ick icr ics ict iia iib iic iii iir iis iit ika ikb ikc iki ikk ikr iks ikt ir- ira irb irc iri irk irr irs irt is- isa isb isc isi isk isr iss ist ita itb itc iti itk its itt k-t ka- kaa kab kac kai kak kar kas kat kba kbb kbc kbi kbk kbr kbs kca kcb kcc kci kck kcr kcs kct kia kib kic kii kik kir kis kit kkb kkc kki kkk kkr kks kkt kra krc kri krk krr krs krt ksa ksb ksc ksi ksk ksr kss kst kta ktb ktc ktk ktr kts ktt ra- raa rab rac rai rak rar ras rat rba rbb rbc rbi rbk rbr rbs rbt rca rcb rcc rci rcr rcs rct ria rib ric rii rik rir ris rit rkb rkc rkk rks rkt rra rrb rrc rri rrk rrr rrs rrt rsa rsb rsc rsi rsk rsr rss rst rta rtb rtc rti rtk rtr rts rtt saa sab sac sai sak sar sas sat sba sbb sbc sbi sbk sbr sbs sbt sca scb scc sci sck scr scs sct sia sib sic sii sik sir sis sit sk- ska skb skc ski skk skr sks skt sr- sra srb src sri srk srr srs srt ss- ssa ssb ssc ssi ssk ssr sss sst sta stb stc sti stk str sts stt taa tab tac tai tak tar tas tat tba tbb tbc tbi tbk tbr tbs tbt tca tcb tcc tci tck tcr tcs tct tia tib tic tii tik tir tis tit tka tkb tkc tkk tkr tks tkt tra trb trc tri trk trr trs trt tsa tsb tsc tsi tsk tsr tss tst tta ttb ttc tti ttk ttr tts ttt