a-be aaaa aaab aaae aaar aaav aaba aabb aaea aaev aaoe aaoo aara aare aaro aava abaa abab abae abar abb- abba abbb abbe abbo abbr abee aber aboa abob aboo abor abov abra abro abva aeer aer- aera aero aeva aoba aora aorb arab arae arar arba arbe area aree areo arev aroa arob aroe aroo aror arr- arra arre arro arrr arva arve arvo avab avao avar avea aveo aver avor avra avre avro avva avvo baaa baar baba babb babe babo babr baer bar- bara barb bare baro barr bava bave bbbb bbeb bear beav beba bebb bebe bebo beeb beer beo- beor bera bere bero berr bevo boab boar boba bobb bobe bobo boea boee boeo boer boob booe boor bor- bora bore boro borr bova bove bovo brab brae brao brav brea breb bree breo brer brev broa brob broe broo bror brrr eaba eara earb eare earo eave ebba ebbo ebbr eber eboe eboo ebor ebro eeea eeee eera eero eeva eora eore erba erbb erbe ereb erer erev erob eroe eroo erra erre erro erve evae evar evea ever evoe evoo evra evre o-eo oaer oara oare obba obbo obea ober oboe obor obra obre obro oera oere ooaa ooba oobe ooer oooo oora oore orab orae orao orar orav orba orbb orbe orbo ore- orea oreb oreo orer oro- oroe oror orra orro orve orvr ovar ovee over ovo- ovoo ovra ovre raab raba rabb rabe rabo raer raob rara rarb rare raro rava rave rbbb rbbr rea- reae reao rear reba rebb rebe rebo reeb reev rera rere rero reva reve revo roab roar rob- roba robb robe robo roea roer roev roob roor rora rore roro rova rove rovo rrrr rver vaar vara vare varr vava vear veba veer veor ver- vera verb vere vero veve vevo voar voer voor vor- vora vore voro vrav vrba vreo vver vvob vvvv