bbbb bibb bibi birb biri birr birt biru biry bitt bitu brit brrr brut bry- btrt btry bttb bubb bubi bubu buir buit buiu bur- burb buri burr burt buru bury but- buti butt buty buyi buyu byit byrt i-by ibri ibtb ibuy ibyi iiii iiit iitr iitt irby iri- iriy irri irti itby itri itry itty itur iuiu iuty rbbb rbbr rib- ribu riby riri riti ritt ritu rrrr rubb rubi rubu ruby ruit ruri ruru ruti rutt rutu ruty ruyi rytt ryyt tbit tbrb tibi tibu tiit tiiu tirb tiri tirr tiru tiry titi titt titu tiyi tri- trib trit trtr trub trut truu try- tryb ttbb tttt tubb tubr tubu tuit tuiu turb turi turr turt turu tury tuti tutt tutu tuty tybi tyir tyr- tyrr tyti tytt tyty ubbi ubii ubir ubit uirr urbi urib uriu urri urry urur urut utby utri utti uttu uuri uuuu uyir ybry yirb yirr yiti yubu yuit yuri yurt yury yutu yuty yuyu yyyy