-ic a-a a-b a-c a-i aaa aab aac aae aai aak aas ab- aba abb abc abe abi abk abs ac- aca acb acc ace aci ack acs aea aeb aec aee aei aek aes ai- aia aib aic aie aii aik ais aka akb akc ake aki akk aks as- asa asb asc ase asi ask ass baa bab bac bae bai bak bas bba bbb bbc bbe bbi bbk bbs bca bcb bcc bce bci bck bcs be- bea beb bec bee bei bek bes bi- bia bib bic bie bii bik bis bka bkb bkc bke bkk bks bsa bsb bsc bse bsi bsk bss c-- caa cab cac cae cai cak cas cba cbb cbc cbe cbi cbk cbs cca ccb ccc cce cci cck ccs ce- cea ceb cec cee cei cek ces ci- cia cib cic cie cii cik cis cka ckb ckc cki cks csa csb csc cse csi csk css eaa eab eac eae eai eak eas eba ebb ebc ebe ebi ebk ebs ec- eca ecb ecc ece eci eck ecs eea eeb eec eee eek ees eia eib eic eie eii eik eis eka ekb ekc eke eki eks es- esa esb esc ese esi esk ess ia- iaa iab iac iae iai ias iba ibb ibc ibe ibi ibk ibs ica icb icc ice ici ick ics ie- iea iec iee iei iek ies iia iib iic iie iii iis ika ikb ikc ike iki ikk iks is- isa isb isc ise isi isk iss ka- kaa kab kac kae kai kak kas kba kbb kbc kbe kbi kbk kbs kca kcb kcc kce kci kck kcs ke- kea keb kec kee kei kek kes kia kib kic kie kii kik kis kkb kkc kke kki kkk kks ksa ksb ksc kse ksi ksk kss saa sab sac sae sai sak sas sba sbb sbc sbe sbi sbk sbs sca scb scc sce sci sck scs se- sea seb sec see sei sek ses sia sib sic sie sii sik sis sk- ska skb skc ske ski skk sks ss- ssa ssb ssc sse ssi ssk sss