bbbb bbci bbeb bbet bbrc bcbc bccc bcci bcec bcer bcet bcie bcit bctc bebb bebe bebi beci beeb beer beet beic beir beit berc bere beri berr bert betc bete beti bett bibb bibe bibi bicc bice bici bieb bier biet birb bire biri birr birt bitc bite bitt brcb brce breb brec bree brei brer bret bric brie brit brrr brtc btcc btec btie btrc btrt bttb cbbc cbcc cbce cbcr cbct cbec cbee cber cbet cbir cbit cbre cbrt cbtc ccbc cccb cccc ccci ccee ccic ccii ccir ccrc ccre ccri ccrt cctb cctc cctt cec- cece ceci cect ceeb ceec cer- cerc cere ceri cert cet- cete ceti cibc cibe cibi cicc cici cicr cict ciee cier ciii ciit cirb circ cire ciri cirr cirt citb cite citi citt crbc crcc crce crcr cre- creb crec cree crei cret crib cric crie crit crrt crtc ctbi ctec ctic ctrc ebbc ebbr ebcc eber ebic ebit ecbc ecbe eccb eccc ecce ecci ecct ecib ecit ecrc ecri ecrr ect- ectc eeee eerc eetc eete eiec eiei eier eire eitb eitc eiti eitr erbb erbe ercc erce ereb erec erei erer eret eric erie erit errc erre etbc etbr etcc etec etee eter etic etre ette etti i-be ibec ibet ibie ibrc ibri ibtb ibtc icbc iccb iccc icci iccr icct icec icee icer icet icrc icre icrr icrt iecc ieet ieie iere ieri iett iiie iiii iiit iirc iitr iitt irbe ircc iree irer iri- iric irie irrc irre irri irte irti itbe itec iter itet itic itie itri rbbb rbbr rcbc rccb rccc rcet rcic rctc rcti rebb rebe recc rece reci recr rect reeb reet reii reir reit rere reri rert rete reti retr rett rib- ribe ricc rice rict rier riet rire riri rite riti ritt rrrr rtcc rtce rtee rtei tbcb tbcc tbce tbit tbrb tccc tctc tecr tect teec teer teet teic teie teir ter- terc tere teri terr tete teti tetr tett tibi ticc tice tie- tiee tiei tier tiet tiit tirb tire tiri tirr titc tite titi titt trcc tre- trec tree trei tret tri- trib tric trie trit trtc trte trtr ttbb tter tttt