aaaa aaab aaar aaba aabb aabt aaoo aara aaro aart aata aatt abaa abab abar abat abax abb- abba abbb abbo abbr abbt aboa abob aboo abor abot abox abra abro abta aoba aora aorb aort arab arar arat arax arba aroa arob aroo aror arr- arra arro arrr arrt arta arto artr artx at-t at-x ataa atab atar atat atax atob ator atot atra atro atrx atta atto attr axar axat axo- axoa axto axxo ba-x baaa baar baat baba babb babo babr bar- bara barb baro barr bart barx bata bato batt baxt bbbb bbox boab boar boat boba bobb bobo boob boor boot boox bor- bora boro borr bort bota botb boto bott boxa brab brao brat brax broa brob broo bror brot brox brrr btaa btob btor btrt bttb oara obba obbo obor obot obox 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 oxa- oxo- oxox oxxo raab raat raba rabb rabo raob rara rarb raro rata rato ratt raxa rbbb rbbr roab roar roat rob- roba robb robo robt roob roor root roox rora roro rort rota roto rotr rott roxa roxo rrat rrrr taa- taar taat taba tabb tabo taoa taor tara tarb taro tarr tart tata tatb tato tatr tatt tax- taxa taxo taxt tbar tbox tbrb tbta toab toat toba tobo tobt tooa toor toot tora toro torr tort torx tota toto totr tott tox- toxa toxo toxt traa trab trao trat trax troa troo trot trox trra trtr ttab ttbb tttt txaa txtr xaar xara xbar xbox xbra xoro xoxo xtar xtra xtro xxxo xxxx