-al a-a a-b a-c a-t aaa aab aac aal aar aas aat ab- aba abb abc abl abr abs abt ac- aca acb acc acl acr acs act al- ala alb alc all alr als alt ar- ara arb arc arl arr ars art as- asa asb asc asl asr ass ast at- ata atb atc atl atr ats att baa bab bac bal bar bas bat bba bbb bbc bbl bbr bbs bbt bca bcb bcc bcl bcr bcs bct bla blb blc bll blr bls blt bra brb brl brr brs brt bsa bsb bsc bsl bsr bss bst bta btb btc btl btr bts btt c-- caa cab cac cal car cas cat cba cbb cbc cbl cbr cbs cbt cca ccb ccc ccl ccr ccs cct cl- cla clb clc cll clr cls clt cra crb crc crl crr crs crt csa csb csc csl csr css cst cta ctb ctc ctl ctr cts ctt la- laa lab lac lal lar las lat lba lbb lbc lbl lbr lbs lbt lca lcb lcc lcl lcr lcs lct lla llb llc lll llr lls llt lra lrb lrc lrr lrs lrt lsa lsb lsc lsl lsr lss lst lta ltb ltc ltl ltr lts ltt ra- raa rab rac ral rar ras rat rba rbb rbc rbl rbr rbs rbt rca rcb rcc rcl rcr rcs rct rla rlc rll rlr rls rlt rra rrb rrc rrl rrr rrs rrt rsa rsb rsc rsl rsr rss rst rta rtb rtc rtl rtr rts rtt saa sab sac sal sar sas sat sba sbb sbc sbl sbr sbs sbt sca scb scc scl scr scs sct sla slb slc sll slr sls slt sr- sra srb src srl srr srs srt ss- ssa ssb ssc ssl ssr sss sst sta stb stc stl str sts stt taa tab tac tal tar tas tat tba tbb tbc tbl tbr tbs tbt tca tcb tcc tcl tcr tcs tct tla tlc tll tlr tls tlt tra trb trc trl trr trs trt tsa tsb tsc tsl tsr tss tst tta ttb ttc ttl ttr tts ttt