a-a a-b a-t aaa aab aam aao aas aat ab- aba abb abm abo abs abt ama amb amm amo ams amt aoa aob aom aoo aos aot as- asa asb asm aso ass ast at- ata atb atm ato ats att baa bab bam bao bas bat bba bbb bbm bbo bbs bbt bma bmb bmm bmo bms bmt boa bob bom boo bos bot bsa bsb bsm bso bss bst bta btb btm bto bts btt m-o maa mab mam mao mas mat mba mbb mbm mbo mbs mbt mma mmb mmm mmo mms mmt moa mob mom moo mos mot msa msb msm mso mss mst mta mtb mtm mto mts mtt oaa oab oam oao oas oat ob- oba obb obm obo obs obt om- oma omb omm omo oms omt oo- ooa oob oom ooo oos oot os- osa osb osm oso oss ost ot- ota otb otm oto ots ott saa sab sam sao sas sat sba sbb sbm sbo sbs sbt sma smb smm smo sms smt soa sob som soo sos sot ss- ssa ssb ssm sso sss sst sta stb stm sto sts stt taa tab tam tao tas tat tba tbb tbm tbo tbs tbt tma tmb tmm tmo tms tmt to- toa tob tom too tos tot tsa tsb tsm tso tss tst tta ttb ttm tto tts ttt