b-tree bbbbbb beebee beegee beerze beeter beezer begger berbee berber bereet berege berere berger berrer berret bertre betere betete bettee better betzet breege breere breeze breger bregge brette ebbert eebree egbere egbert eggert erbree errett etgert etrez gbegbe gebbet gebert geegee geertz geezer gegger gerber gerege gerger gerret gertte getter greete greetz greeze greger gregge gregre greter grette gteter r-tree regret reteer reteet retere retree retret retter t-tree teebee teetee teeter terete terrer terret terter tertre terzet tetete tetter treete treget tretee trette tzetze zeebee zegrze zerbet zertz zezere