a-a a-b aaa aab aam aap aas ab- aba abb abm abp abs ama amb amm amp ams ap- apa apb apm app aps as- asa asb asm asp ass b-p baa bab bam bap bas bba bbb bbm bbp bbs bma bmb bmm bmp bms bpa bpb bpm bpp bps bsa bsb bsm bsp bss maa mab mam map mas mba mbb mbm mbp mbs mma mmb mmm mmp mms mpa mpb mpm mpp mps msa msb msm msp mss p-p paa pab pam pap pas pba pbb pbm pbp pbs pma pmb pmm pmp pms ppa ppb ppm ppp pps ps- psa psb psm psp pss saa sab sam sap sas sba sbb sbm sbp sbs sma smb smm smp sms spa spb spm spp sps ss- ssa ssb ssm ssp sss