-al a-a a-b a-c a-t aaa aab aac aak aal aat ab- aba abb abc abk abl abt ac- aca acb acc ack acl act aka akb akc akk akl al- ala alb alc alk all alt at- ata atb atc atl att baa bab bac bak bal bat bba bbb bbc bbk bbl bbt bca bcb bcc bck bcl bct bka bkb bkc bkk bkl bkt bla blb blc blk bll blt bta btb btc btk btl btt c-- caa cab cac cak cal cat cba cbb cbc cbk cbl cbt cca ccb ccc cck ccl cct cka ckb ckc ckt cl- cla clb clc clk cll clt cta ctb ctc ctk ctl ctt k-t ka- kaa kab kac kak kal kat kba kbb kbc kbk kbl kca kcb kcc kck kcl kct kkb kkc kkk kkl kkt kl- kla klb klc klt kta ktb ktc ktk ktl ktt la- laa lab lac lak lal lat lba lbb lbc lbk lbl lbt lca lcb lcc lck lcl lct lka lkb lkl lkt lla llb llc llk lll llt lta ltb ltc ltk ltl ltt taa tab tac tak tal tat tba tbb tbc tbk tbl tbt tca tcb tcc tck tcl tct tka tkb tkc tkk tkl tkt tla tlc tlk tll tlt tta ttb ttc ttk ttl ttt