aaaa aaab aaar aaba aabb aabt aaoo aara aaro aart aata aatt abaa abab abar abat abb- abba abbb abbo abbr abbt aboa abob aboo abor abot abra abro abta aoba aora aorb aort arab arar arat arba aroa arob aroo aror arr- arra arro arrr arrt arta arto artr at-t ataa atab atar atat atob ator atot atra atro atta atto attr baaa baar baat baba babb babo babr bar- bara barb baro barr bart bata bato batt bbbb boab boar boat boba bobb bobo boob boor boot bor- bora boro borr bort bota botb boto bott brab brao brat broa brob broo bror brot brrr btaa btob btor btrt bttb oara obba obbo obor obot obra obro ooaa ooba oooo oora oort ootb orab orao orar orat orba orbb orbo oro- oror orot orra orro orta orto otar oto- otoo otor otra otro otta otto raab raat raba rabb rabo raob rara rarb raro rata rato ratt rbbb rbbr roab roar roat rob- roba robb robo robt roob roor root rora roro rort rota roto rotr rott rrat rrrr taa- taar taat taba tabb tabo taoa taor tara tarb taro tarr tart tata tatb tato tatr tatt tbar tbrb tbta toab toat toba tobo tobt tooa toor toot tora toro torr tort tota toto totr tott traa trab trao trat troa troo trot trra trtr ttab ttbb tttt