a-a a-b aaa aab aam aao aap aas ab- aba abb abm abo abp abs ama amb amm amo amp ams aoa aob aom aoo aop aos ap- apa apb apm apo app aps as- asa asb asm aso asp ass b-p baa bab bam bao bap bas bba bbb bbm bbo bbp bbs bma bmb bmm bmo bmp bms boa bob bom boo bop bos bpa bpb bpm bpo bpp bps bsa bsb bsm bso bsp bss m-o maa mab mam mao map mas mba mbb mbm mbo mbp mbs mma mmb mmm mmo mmp mms moa mob mom moo mop mos mpa mpb mpm mpo mpp mps msa msb msm mso msp mss oaa oab oam oao oap oas ob- oba obb obm obo obp obs om- oma omb omm omo omp oms oo- ooa oob oom ooo oop oos op- opa opb opm opo opp ops os- osa osb osm oso osp oss p-p paa pab pam pao pap pas pba pbb pbm pbo pbp pbs pma pmb pmm pmo pmp pms poa pob pom poo pop pos ppa ppb ppm ppo ppp pps ps- psa psb psm pso psp pss saa sab sam sao sap sas sba sbb sbm sbo sbp sbs sma smb smm smo smp sms soa sob som soo sop sos spa spb spm spo spp sps ss- ssa ssb ssm sso ssp sss