-tree b-r-k bbbee be-er bebek beber beebe beeft beeke beete beffe begee beget begge beker bekke berbe bereg berek beret berge berk- berke berre berte betee beter betke betre bett- bette breef breek breer breet breg- brege bregg breke brere brett brrrr btr-t ebber ebbet eberg ebert eeeee efere efetf effer effet efter egger egrek egret ekker erbbe erber erege erere erte erter eteke etete etree etrek etter febre feere feret ferr- ferre ferte feter fette freek freer freet frege freke frere frett ftrtt gbeke gberg gbfte geber gebet gebke gebre geere geert geete gefek gefte gegge gerbe gerke gerre gertt getee geter gette grebe greef greek greer greet grefe greff grege gregg grete grett grftr grrrr gtk-- k-gee k-t-b kebbe kebek keber keefe keere kefee keget kerek keret kerre ketek keter kette kreef kreek kreke krete rebbe rebeg reber rebet reefe reeft reege reere refer refet reffe reger reget regge regtt rekke rere- reree reret retee reter retrg rette rt-rk tbtbt teber tebet teege tefe tegre teket tekke terek teret terge terre tert- teter tetr- tette treer treet trefe treff treg- trere trete trett ttttt