a-a a-b aaa aab aad aag aan aao ab- aba abb abd abg abn abo ad- ada adb add adg adn ado ag- aga agb agd agg agn ago an- ana anb and ang ann ano aoa aob aod aog aon aoo baa bab bad bag ban bao bba bbb bbd bbg bbn bbo bda bdb bdd bdg bdo bga bgb bgd bgg bgn bgo bna bnb bnd bng bnn bno boa bob bod bog bon boo daa dab dad dag dan dao dba dbb dbd dbg dbn dbo dda ddb ddd ddg ddn ddo dga dgd dgg dgn dna dnb dnd dng dnn dno doa dob dod dog don doo g-d gaa gab gad gag gan gao gba gbd gbg gbn gbo gda gdb gdd gdn gdo gga ggb ggd ggg ggn ggo gna gnb gnd gnn gno goa gob god gog gon goo naa nab nad nag nan nao nba nbb nbd nbg nbn nbo nda ndb ndd ndg ndn ndo nga ngb ngd ngg ngn ngo nna nnb nng nnn nno no- noa nob nod nog non noo oaa oab oad oag oan oao ob- oba obb obd obg obn obo oda odb odd odg odn odo oga ogd ogg ogn ogo on- ona onb ond ong onn ono oo- ooa oob ood oog oon ooo