bbbbbb bobrok bokoro booboo borbor borkou boroko bororo botoko botoro boubou boukou bourou boutob brokkr brotto brubru brutto bububu bukkur bukoto bukuru burbot burbur burkut burotu buruku burutu butbro buttto buutuo kkoktu koboko kokoku kokoro kokott kokubo kookoo kootoo koottu korbut korkor korkut kororo korubo koruru kotoko kottur kotuku koubou koukou kouoro kourou kourtt koutou kuroko kurort kururu obturb ookroo oooooo orrour ottoor outour outtro roboto rokkor rokuko rokuro rotork rotour rotout rotrou routot rubbot rubout rubro- rubutu rukutu rurutu rutour tkoutt toboot tobruk tokuko tokuro tookto tootoo tororo tortor tortou totoro totrot tourou toutou toutuo trokut trotro tuktuk tuotuo turbo- turbot turko- turtuk turtur tururu tutour tuttut u-boot utkoor utroor utukku utukur