b-p bbb bbc bbm bbo bbp bcb bcc bcm bco bcp bmb bmc bmm bmo bmp bob boc bom boo bop bpb bpc bpm bpo bpp c-- cbb cbc cbm cbo cbp ccb ccc ccm cco ccp cmb cmc cmm cmo cmp co- cob coc com coo cop cpb cpc cpm cpo cpp m-o mbb mbc mbm mbo mbp mc- mcb mcc mcm mco mcp mmb mmc mmm mmo mmp mob moc mom moo mop mpb mpc mpm mpo mpp ob- obb obc obm obo obp oc- ocb occ ocm oco ocp om- omb omc omm omo omp oo- oob ooc oom ooo oop op- opb opc opm opo opp p-p pbb pbc pbm pbo pbp pcb pcc pcm pco pcp pmb pmc pmm pmo pmp pob poc pom poo pop ppb ppc ppm ppo ppp