a-a a-b a-c a-q aaa aab aac aaq aar aas ab- aba abb abc abq abr abs ac- aca acb acc acq acr acs aqa aqc aqr aqs ar- ara arb arc arq arr ars as- asa asb asc asq asr ass baa bab bac baq bar bas bba bbb bbc bbq bbr bbs bca bcb bcc bcq bcr bcs bqc bra brb brq brr brs bsa bsb bsc bsr bss c-- caa cab cac caq car cas cba cbb cbc cbq cbr cbs cca ccb ccc ccr ccs cqa cqb cqc cqs cra crb crc crq crr crs csa csb csc csq csr css qaa qac qar qas qba qbc qbq qbs qca qcc qcs qqq qra qrb qrc qrs qsa qsc qsr ra- raa rab rac raq rar ras rba rbb rbc rbr rbs rca rcb rcc rcr rcs rqc rqs rra rrb rrc rrq rrr rrs rsa rsb rsc rsq rsr rss saa sab sac saq sar sas sba sbb sbc sbq sbr sbs sca scb scc scr scs sqa sqq sqr sqs sr- sra srb src srq srr srs ss- ssa ssb ssc ssq ssr sss