b-tree bbbbbb beebee beegee beeter begger berbee berber bereet berege berere berger berrer berret bertre betere betete bettee better bewter breege breere breger bregge brette brewer brewet ebbert eebree egbere egbert eggert erbree errett etgert ewerer gbegbe gebbet gebert geegee gegger gerber gerege gerger gerret gertte getter getwet greete greger gregge gregre greter grette gteter gwereg gwerre r-tree rebrew regret regrew reteer reteet retere retree retret retter rewere t-tree teebee teetee teeter terete terrer terret terter tertre tetete tetter treete treewe treget tregew tretee trette webber weegee weewee wegert wertew wetere wetter wewere wrette