a-a a-b a-i aaa aab aag aai aak aas ab- aba abb abg abi abk abs ag- aga agb agg agi agk ags ai- aia aib aig aii aik ais aka akb akg aki akk aks as- asa asb asg asi ask ass baa bab bag bai bak bas bba bbb bbg bbi bbk bbs bga bgb bgg bgi bgk bgs bi- bia bib big bii bik bis bka bkb bkg bkk bks bsa bsb bsg bsi bsk bss gaa gab gag gai gak gas gba gbg gbi gbk gbs gga ggb ggg ggi ggs gia gib gig gii gik gis gka gkb gks gsa gsb gsg gsi gsk gss ia- iaa iab iag iai ias iba ibb ibg ibi ibk ibs iga igb igg igi igk igs iia iib iii iis ika ikb iki ikk iks is- isa isb isg isi isk iss ka- kaa kab kag kai kak kas kba kbb kbi kbk kbs kga kgb kgi kgs kia kib kig kii kik kis kkb kki kkk kks ksa ksb ksg ksi ksk kss saa sab sag sai sak sas sba sbb sbg sbi sbk sbs sga sgb sgg sgi sgk sgs sia sib sig sii sik sis sk- ska skb skg ski skk sks ss- ssa ssb ssg ssi ssk sss