-al a-a a-b a-c aaa aab aac aak aal aar ab- aba abb abc abk abl abr ac- aca acb acc ack acl acr aka akb akc akk akl akr al- ala alb alc alk all alr ar- ara arb arc ark arl arr baa bab bac bak bal bar bba bbb bbc bbk bbl bbr bca bcb bcc bck bcl bcr bka bkb bkc bkk bkl bkr bla blb blc blk bll blr bra brb brk brl brr c-- caa cab cac cak cal car cba cbb cbc cbk cbl cbr cca ccb ccc cck ccl ccr cka ckb ckc cl- cla clb clc clk cll clr cra crb crc crk crl crr ka- kaa kab kac kak kal kar kba kbb kbc kbk kbl kbr kca kcb kcc kck kcl kcr kkb kkc kkk kkl kkr kl- kla klb klc klr kra krc krk krl krr la- laa lab lac lak lal lar lba lbb lbc lbk lbl lbr lca lcb lcc lck lcl lcr lka lkb lkl lkr lla llb llc llk lll llr lra lrb lrc lrk lrr ra- raa rab rac rak ral rar rba rbb rbc rbk rbl rbr rca rcb rcc rcl rcr rkb rkc rkk rla rlc rll rlr rra rrb rrc rrk rrl rrr