-al a-a a-b aaa aab aad aal aar ab- aba abb abd abl abr ad- ada adb add adl adr al- ala alb ald all alr ar- ara arb ard arl arr baa bab bad bal bar bba bbb bbd bbl bbr bda bdb bdd bdl bdr bla blb bld bll blr bra brb brd brl brr daa dab dad dal dar dba dbb dbd dbl dbr dda ddb ddd ddl ddr dl- dla dlb dld dll dlr dra drb drd drl drr la- laa lab lad lal lar lba lbb lbd lbl lbr lda ldb ldd ldl ldr lla llb lld lll llr lra lrb lrd lrr ra- raa rab rad ral rar rba rbb rbd rbl rbr rda rdb rdd rdl rdr rla rld rll rlr rra rrb rrd rrl rrr