bbbb bbin bbpr bibb bibi biin bin- bini binn bint bipp birb biri birn birr birt bitt bnib bnin bnpp bnrr bpti brin brit brrr btbp btrt bttb ibri ibtb iiii iiit iitr iitt init inni innr inp- inpi inpp inpt inri inti intn intp intr ipin ippr ipri irbp iri- irin irip irri irti irtp itin itri n-ii nbpp nbti nibi niip niir niit nini nipr nipt nirt nitb niti nitr nnit nnnn nnpi nnpr nntn npin npri nprt nptn nrpn nttr pibb pibi piip pini pinn pinp pint pipi pipp piri pirn pirr piti pitr pitt pnin pnpp pntr ppib pppn pppp pptn pptt pri- prii prin prnp prri prti prtp prtr rbbb rbbr rib- riin rinn ripi ripp ripr ript riri riti ritt rnbr rnin rnnt rntp rpii rppn rptn rrrr rttp tbit tbrb tbtp tibi tiit tini tinn tint tip- tipi tipp tipt tirb tiri tirr titi titp titt tpir tppp tppr tptp tptr tri- trib trin trip trit trpn trpp trtr ttbb tttt