a-a a-b aaa aab aam aao aap aar ab- aba abb abm abo abp abr ama amb amm amo amp amr aoa aob aom aoo aop aor ap- apa apb apm apo app apr ar- ara arb arm aro arp arr b-p baa bab bam bao bap bar bba bbb bbm bbo bbp bbr bma bmb bmm bmo bmp bmr boa bob bom boo bop bor bpa bpb bpm bpo bpp bpr bra brb brm bro brp brr m-o m-r maa mab mam mao map mar mba mbb mbm mbo mbp mbr mma mmb mmm mmo mmp mmr moa mob mom moo mop mor mpa mpb mpm mpo mpp mpr mra mrb mrm mro mrp mrr oaa oab oam oao oap oar ob- oba obb obm obo obp obr om- oma omb omm omo omp omr oo- ooa oob oom ooo oop oor op- opa opb opm opo opp opr or- ora orb orm oro orp orr p-p paa pab pam pao pap par pba pbb pbm pbo pbp pbr pma pmb pmm pmo pmp pmr poa pob pom poo pop por ppa ppb ppm ppo ppp ppr pra prb prm pro prp prr ra- raa rab ram rao rap rar rba rbb rbm rbo rbp rbr rma rmb rmm rmo rmp rmr roa rob rom roo rop ror rpa rpb rpm rpo rpp rpr rra rrb rrm rrp rrr