a-a a-b a-q a-t aaa aab aaq aar aat aau ab- aba abb abq abr abt abu aqa aqr aqt ar- ara arb arq arr art aru at- ata atb atr att atu au- aua aub aur aut b-u baa bab baq bar bat bau bba bbb bbq bbr bbt bbu bqt bra brb brq brr brt bru bta btb btq btr btt btu bua bub bur but buu qaa qar qat qau qba qbq qqq qqu qra qrb qrt qru qta qtq qtr qu- qua qur qut ra- raa rab raq rar rat rau rba rbb rbr rbt rbu rra rrb rrq rrr rrt rru rta rtb rtq rtr rtt rtu rua rub rur rut ruu taa tab taq tar tat tau tba tbb tbr tbt tbu tra trb trq trr trt tru tta ttb ttr ttt ttu tua tub tur tut tuu ua- uaa uab uaq uar uat uau uba ubb ubr ubt ubu ur- ura urb urr urt uru uta utb utr utt utu uua uur uut uuu