a-a a-b aaa aab aam aao aap ab- aba abb abm abo abp ama amb amm amo amp aoa aob aom aoo aop ap- apa apb apm apo app b-p baa bab bam bao bap bba bbb bbm bbo bbp bma bmb bmm bmo bmp boa bob bom boo bop bpa bpb bpm bpo bpp m-o maa mab mam mao map mba mbb mbm mbo mbp mma mmb mmm mmo mmp moa mob mom moo mop mpa mpb mpm mpo mpp oaa oab oam oao oap ob- oba obb obm obo obp om- oma omb omm omo omp oo- ooa oob oom ooo oop op- opa opb opm opo opp p-p paa pab pam pao pap pba pbb pbm pbo pbp pma pmb pmm pmo pmp poa pob pom poo pop ppa ppb ppm ppo ppp