a-a a-b a-c a-z aaa aab aac aam aar aaz ab- aba abb abc abm abr abz ac- aca acb acc acm acr acz ama amb amc amm amr amz ar- ara arb arc arm arr arz az- aza azb azm azz baa bab bac bam bar baz bba bbb bbc bbm bbr bca bcb bcc bcm bcr bcz bma bmb bmc bmm bmr bmz bra brb brm brr brz bza bzr bzz c-- caa cab cac cam car caz cba cbb cbc cbm cbr cbz cca ccb ccc ccm ccr ccz cma cmb cmc cmm cmr cra crb crc crm crr crz cz- czc czm m-r maa mab mac mam mar maz mba mbb mbc mbm mbr mc- mca mcb mcc mcm mcr mcz mma mmb mmc mmm mmr mmz mra mrb mrc mrm mrr mrz mza mzb mzm ra- raa rab rac ram rar raz rba rbb rbc rbm rbr rca rcb rcc rcm rcr rma rmb rmc rmm rmr rra rrb rrc rrm rrr rza rzb rzm zaa zab zac zam zar zaz zbb zbc zbm zbr zma zmb zmc zmm zzr zzz