a-a a-b a-c aaa aab aac aad aag aao ab- aba abb abc abd abg abo ac- aca acb acc acd acg aco ad- ada adb adc add adg ado ag- aga agb agc agd agg ago aoa aob aoc aod aog aoo baa bab bac bad bag bao bba bbb bbc bbd bbg bbo bca bcb bcc bcd bcg bco bda bdb bdc bdd bdg bdo bga bgb bgc bgd bgg bgo boa bob boc bod bog boo c-- caa cab cac cad cag cao cba cbb cbc cbd cbg cbo cca ccb ccc ccd ccg cco cda cdb cdc cdd cdg cdo cga cgb cgc cgd cgg cgo co- coa cob coc cod cog coo daa dab dac dad dag dao dba dbb dbc dbd dbg dbo dca dcb dcc dcd dcg dco dda ddb ddc ddd ddg ddo dga dgc dgd dgg doa dob doc dod dog doo g-d gaa gab gac gad gag gao gba gbc gbd gbg gbo gca gcb gcc gcd gcg gco gda gdb gdc gdd gdo gga ggb ggc ggd ggg ggo goa gob goc god gog goo oaa oab oac oad oag oao ob- oba obb obc obd obg obo oc- oca ocb occ ocd ocg oco oda odb odc odd odg odo oga ogc ogd ogg ogo oo- ooa oob ooc ood oog ooo