a-a a-b aaa aab aag aao aap ab- aba abb abg abo abp ag- aga agb agg ago agp aoa aob aog aoo aop ap- apa apb apg apo app b-p baa bab bag bao bap bba bbb bbg bbo bbp bga bgb bgg bgo bgp boa bob bog boo bop bpa bpb bpg bpo bpp g-p gaa gab gag gao gap gba gbg gbo gbp gga ggb ggg ggo ggp goa gob gog goo gop gpa gpb gpg gpo gpp oaa oab oag oao oap ob- oba obb obg obo obp oga ogg ogo ogp oo- ooa oob oog ooo oop op- opa opb opg opo opp p-p paa pab pag pao pap pba pbb pbg pbo pbp pga pgb pgg pgo pgp poa pob pog poo pop ppa ppb ppg ppo ppp