a-a a-b a-t aaa aab aam aas aat ab- aba abb abm abs abt ama amb amm ams amt as- asa asb asm ass ast at- ata atb atm ats att baa bab bam bas bat bba bbb bbm bbs bbt bma bmb bmm bms bmt bsa bsb bsm bss bst bta btb btm bts btt maa mab mam mas mat mba mbb mbm mbs mbt mma mmb mmm mms mmt msa msb msm mss mst mta mtb mtm mts mtt saa sab sam sas sat sba sbb sbm sbs sbt sma smb smm sms smt ss- ssa ssb ssm sss sst sta stb stm sts stt taa tab tam tas tat tba tbb tbm tbs tbt tma tmb tmm tms tmt tsa tsb tsm tss tst tta ttb ttm tts ttt