-ic a-a a-b a-c a-i a-t aaa aab aac aae aai aak aas aat ab- aba abb abc abe abi abk abs abt ac- aca acb acc ace aci ack acs act aea aeb aec aee aei aek aes aet ai- aia aib aic aie aii aik ais ait aka akb akc ake aki akk aks as- asa asb asc ase asi ask ass ast at- ata atb atc ate ati ats att baa bab bac bae bai bak bas bat bba bbb bbc bbe bbi bbk bbs bbt bca bcb bcc bce bci bck bcs bct be- bea beb bec bee bei bek bes bet bi- bia bib bic bie bii bik bis bit bka bkb bkc bke bkk bks bkt bsa bsb bsc bse bsi bsk bss bst bta btb btc bte bti btk bts btt c-- caa cab cac cae cai cak cas cat cba cbb cbc cbe cbi cbk cbs cbt cca ccb ccc cce cci cck ccs cct ce- cea ceb cec cee cei cek ces cet ci- cia cib cic cie cii cik cis cit cka ckb ckc cki cks ckt csa csb csc cse csi csk css cst cta ctb ctc cte cti ctk cts ctt eaa eab eac eae eai eak eas eat eba ebb ebc ebe ebi ebk ebs ebt ec- eca ecb ecc ece eci eck ecs ect eea eeb eec eee eek ees eet eia eib eic eie eii eik eis eit eka ekb ekc eke eki eks ekt es- esa esb esc ese esi esk ess est eta etb etc ete eti etk ets ett ia- iaa iab iac iae iai ias iat iba ibb ibc ibe ibi ibk ibs ibt ica icb icc ice ici ick ics ict ie- iea iec iee iei iek ies iet iia iib iic iie iii iis iit ika ikb ikc ike iki ikk iks ikt is- isa isb isc ise isi isk iss ist ita itb itc ite iti itk its itt k-t ka- kaa kab kac kae kai kak kas kat kba kbb kbc kbe kbi kbk kbs kca kcb kcc kce kci kck kcs kct ke- kea keb kec kee kei kek kes ket kia kib kic kie kii kik kis kit kkb kkc kke kki kkk kks kkt ksa ksb ksc kse ksi ksk kss kst kta ktb ktc kte ktk kts ktt saa sab sac sae sai sak sas sat sba sbb sbc sbe sbi sbk sbs sbt sca scb scc sce sci sck scs sct se- sea seb sec see sei sek ses set sia sib sic sie sii sik sis sit sk- ska skb skc ske ski skk sks skt ss- ssa ssb ssc sse ssi ssk sss sst sta stb stc ste sti stk sts stt taa tab tac tae tai tak tas tat tba tbb tbc tbe tbi tbk tbs tbt tca tcb tcc tce tci tck tcs tct te- tea teb tec tee tei tek tes tet tia tib tic tie tii tik tis tit tka tkb tkc tke tkk tks tkt tsa tsb tsc tse tsi tsk tss tst tta ttb ttc tte tti ttk tts ttt