a-a a-b a-c aaa aab aac aae aag aao aas ab- aba abb abc abe abg abo abs ac- aca acb acc ace acg aco acs aea aeb aec aee aeg aeo aes ag- aga agb agc age agg ago ags aoa aob aoc aoe aog aoo aos as- asa asb asc ase asg aso ass baa bab bac bae bag bao bas bba bbb bbc bbe bbg bbo bbs bca bcb bcc bce bcg bco bcs be- bea beb bec bee beg beo bes bga bgb bgc bge bgg bgo bgs boa bob boc boe bog boo bos bsa bsb bsc bse bsg bso bss c-- caa cab cac cae cag cao cas cba cbb cbc cbe cbg cbo cbs cca ccb ccc cce ccg cco ccs ce- cea ceb cec cee ceg ceo ces cga cgb cgc cge cgg cgo cgs co- coa cob coc coe cog coo cos csa csb csc cse csg cso css eaa eab eac eae eag eao eas eba ebb ebc ebe ebg ebo ebs ec- eca ecb ecc ece ecg eco ecs eea eeb eec eee eeg eeo ees ega egb egc ege egg ego egs eo- eoa eob eoc eoe eog eoo eos es- esa esb esc ese esg eso ess gaa gab gac gae gag gao gas gba gbc gbe gbg gbo gbs gca gcb gcc gce gcg gco gcs ge- gea geb gec gee geg geo ges gga ggb ggc ggg ggo ggs goa gob goc goe gog goo gos gsa gsb gsc gse gsg gso gss oaa oab oac oae oag oao oas ob- oba obb obc obe obg obo obs oc- oca ocb occ ocg oco ocs oea oeb oec oee oeg oeo oes oga ogc oge ogg ogo ogs oo- ooa oob ooc oog ooo oos os- osa osb osc ose osg oso oss saa sab sac sae sag sao sas sba sbb sbc sbe sbg sbo sbs sca scb scc sce scg sco scs se- sea seb sec see seg seo ses sga sgb sgc sge sgg sgo sgs soa sob soc soe sog soo sos ss- ssa ssb ssc sse ssg sso sss