bbbb bbeb bbrc bcbc bccc bcec bcer bcor bcvo bebb bebe bebo beeb beer beo- beor berc bere bero berr bevo bobb bobe bobo boce boco boec boee boeo boer boob booc booe boor bor- bore boro borr bove bovo brcb brce breb brec bree breo brer brev brob broc broe broo bror brrr c-bo cbbc cbcc cbce cbcr cbec cbee cber cbre cbvb cbve cbvr ccbc cccb cccc cccv ccee ccob ccoc ccrc ccre ccvo cec- cece ceco ceeb ceec ceor cer- cerc cere cero cevo cobb cobe cobo coce coco coob cor- corb corc core coro corr cove covo crbc crcc crce crcr cre- creb crec cree creo crob croc croe croo cror cvcc cver cvrr ebbc ebbo ebbr ebcc eber eboe eboo ebor ebro ecbc ecbe eccb eccc ecce ecco eco- ecrc ecrr ecrv eeee eeoc eerc eero eore erbb erbe ercc erce ereb erec erer erev erob eroc eroe eroo errc erre erro erve ever evoe evoo evre o-eo obbo obec ober oboe obor obre obro ocbc occc oce ocee ocre ocro ocrr oec- oecc oeec oere oobe oocr ooer oooo oore orbb orbe orbo orce orco ore- oreb orec oreo orer oro- oroe oror orro orve orvr ovee over ovo- ovoo ovre rbbb rbbr rcbc rcbo rccb rccc rcvr rebb rebe rebo recc rece recr reeb reev rere rero reve revo rob- robb robe robo rocc roce roco roer roev roob roor rorc rore roro rove rovo rrrr rv-c rver vbcc vecc veer veor ver- verb vere vero veve vevo voce voer vooc voor vor- vore voro vreo vroc vver vvob vvvv