-ic a-a a-b a-c a-i aaa aab aac aae aag aai aak aas ab- aba abb abc abe abg abi abk abs ac- aca acb acc ace acg aci ack acs aea aeb aec aee aeg aei aek aes ag- aga agb agc age agg agi agk ags ai- aia aib aic aie aig aii aik ais aka akb akc ake akg aki akk aks as- asa asb asc ase asg asi ask ass baa bab bac bae bag bai bak bas bba bbb bbc bbe bbg bbi bbk bbs bca bcb bcc bce bcg bci bck bcs be- bea beb bec bee beg bei bek bes bga bgb bgc bge bgg bgi bgk bgs bi- bia bib bic bie big bii bik bis bka bkb bkc bke bkg bkk bks bsa bsb bsc bse bsg bsi bsk bss c-- caa cab cac cae cag cai cak cas cba cbb cbc cbe cbg cbi cbk cbs cca ccb ccc cce ccg cci cck ccs ce- cea ceb cec cee ceg cei cek ces cga cgb cgc cge cgg cgi cgs ci- cia cib cic cie cig cii cik cis cka ckb ckc cki cks csa csb csc cse csg csi csk css eaa eab eac eae eag eai eak eas eba ebb ebc ebe ebg ebi ebk ebs ec- eca ecb ecc ece ecg eci eck ecs eea eeb eec eee eeg eek ees ega egb egc ege egg egi egs eia eib eic eie eig eii eik eis eka ekb ekc eke ekg eki eks es- esa esb esc ese esg esi esk ess gaa gab gac gae gag gai gak gas gba gbc gbe gbg gbi gbk gbs gca gcb gcc gce gcg gci gck gcs ge- gea geb gec gee geg gei gek ges gga ggb ggc ggg ggi ggs gia gib gic gie gig gii gik gis gka gkb gks gsa gsb gsc gse gsg gsi gsk gss ia- iaa iab iac iae iag iai ias iba ibb ibc ibe ibg ibi ibk ibs ica icb icc ice icg ici ick ics ie- iea iec iee ieg iei iek ies iga igb igc ige igg igi igk igs iia iib iic iie iii iis ika ikb ikc ike iki ikk iks is- isa isb isc ise isg isi isk iss ka- kaa kab kac kae kag kai kak kas kba kbb kbc kbe kbi kbk kbs kca kcb kcc kce kcg kci kck kcs ke- kea keb kec kee keg kei kek kes kga kgb kgc kgi kgs kia kib kic kie kig kii kik kis kkb kkc kke kki kkk kks ksa ksb ksc kse ksg ksi ksk kss saa sab sac sae sag sai sak sas sba sbb sbc sbe sbg sbi sbk sbs sca scb scc sce scg sci sck scs se- sea seb sec see seg sei sek ses sga sgb sgc sge sgg sgi sgk sgs sia sib sic sie sig sii sik sis sk- ska skb skc ske skg ski skk sks ss- ssa ssb ssc sse ssg ssi ssk sss