a-a a-b aaa aab aam aap aar aas ab- aba abb abm abp abr abs ama amb amm amp amr ams ap- apa apb apm app apr aps ar- ara arb arm arp arr ars as- asa asb asm asp asr ass b-p baa bab bam bap bar bas bba bbb bbm bbp bbr bbs bma bmb bmm bmp bmr bms bpa bpb bpm bpp bpr bps bra brb brm brp brr brs bsa bsb bsm bsp bsr bss m-r maa mab mam map mar mas mba mbb mbm mbp mbr mbs mma mmb mmm mmp mmr mms mpa mpb mpm mpp mpr mps mra mrb mrm mrp mrr mrs msa msb msm msp msr mss p-p paa pab pam pap par pas pba pbb pbm pbp pbr pbs pma pmb pmm pmp pmr pms ppa ppb ppm ppp ppr pps pra prb prm prp prr prs ps- psa psb psm psp psr pss ra- raa rab ram rap rar ras rba rbb rbm rbp rbr rbs rma rmb rmm rmp rmr rms rpa rpb rpm rpp rpr rps rra rrb rrm rrp rrr rrs rsa rsb rsm rsp rsr rss saa sab sam sap sar sas sba sbb sbm sbp sbr sbs sma smb smm smp smr sms spa spb spm spp spr sps sr- sra srb srm srp srr srs ss- ssa ssb ssm ssp ssr sss