-al a-a a-b a-t aaa aab aal aar aat ab- aba abb abl abr abt al- ala alb all alr alt ar- ara arb arl arr art at- ata atb atl atr att baa bab bal bar bat bba bbb bbl bbr bbt bla blb bll blr blt bra brb brl brr brt bta btb btl btr btt la- laa lab lal lar lat lba lbb lbl lbr lbt lla llb lll llr llt lra lrb lrr lrt lta ltb ltl ltr ltt ra- raa rab ral rar rat rba rbb rbl rbr rbt rla rll rlr rlt rra rrb rrl rrr rrt rta rtb rtl rtr rtt taa tab tal tar tat tba tbb tbl tbr tbt tla tll tlr tlt tra trb trl trr trt tta ttb ttl ttr ttt