bbbb bbci bbdd bbrc bcbc bccc bcci bd-r bdbc bddc bdii bibb bibi bicc bici bidi bidr birb bird biri birr brcb bric brid brrr c-cd cbbc cbcc cbcr cbdb cbdc cbdi cbid cbir cbrd ccbc cccb cccc ccci ccdc ccdi ccdr ccic ccid ccii ccir ccrc ccri cd-r cddb cddr cdic cdii cibc cibi cicc cici cicr cidc cidi cidr ciid ciii cirb circ ciri cirr crbc crcc crcr crdc crib cric dbcc dcbc dccb dccc dcci dcdb dcii dddd ddrc dibb dici didi diii dird dirr drbc drib dric ibid ibrc ibrd ibri icbc icbd iccb iccc icci iccr icdc icdd icrc icrr idcr idic idid idir idrc iicd iiii iirc ircc ircd irdc iri- iric irid irrc irri rbbb rbbr rcbc rccb rccc rcdc rcic rcid rcrd rib- ricc ridc ridd ridi riri rrrr