b-p bbb bbm bbo bbp bbs bmb bmm bmo bmp bms bob bom boo bop bos bpb bpm bpo bpp bps bsb bsm bso bsp bss m-o mbb mbm mbo mbp mbs mmb mmm mmo mmp mms mob mom moo mop mos mpb mpm mpo mpp mps msb msm mso msp mss ob- obb obm obo obp obs om- omb omm omo omp oms oo- oob oom ooo oop oos op- opb opm opo opp ops os- osb osm oso osp oss p-p pbb pbm pbo pbp pbs pmb pmm pmo pmp pms pob pom poo pop pos ppb ppm ppo ppp pps ps- psb psm pso psp pss sbb sbm sbo sbp sbs smb smm smo smp sms sob som soo sop sos spb spm spo spp sps ss- ssb ssm sso ssp sss