-al -ol a-a a-b a-t aaa aab aal aao aar aat ab- aba abb abl abo abr abt al- ala alb all alo alr alt aoa aob aol aoo aor aot ar- ara arb arl aro arr art at- ata atb atl ato atr att baa bab bal bao bar bat bba bbb bbl bbo bbr bbt bla blb bll blo blr blt boa bob bol boo bor bot bra brb brl bro brr brt bta btb btl bto btr btt la- laa lab lal lao lar lat lba lbb lbl lbo lbr lbt lla llb lll llo llr llt loa lob lol loo lor lot lra lrb lro lrr lrt lta ltb ltl lto ltr ltt oaa oab oal oao oar oat ob- oba obb obl obo obr obt ola olb oll olo olt oo- ooa oob ool ooo oor oot or- ora orb orl oro orr ort ot- ota otb otl oto otr ott ra- raa rab ral rao rar rat rba rbb rbl rbo rbr rbt rla rll rlo rlr rlt roa rob rol roo ror rot rra rrb rrl rrr rrt rta rtb rtl rto rtr rtt taa tab tal tao tar tat tba tbb tbl tbo tbr tbt tla tll tlo tlr tlt to- toa tob tol too tor tot tra trb trl tro trr trt tta ttb ttl tto ttr ttt