-tree e-ten eeeee eeler eener eenet eepee eeten eleet elele elene ellel ellen eller ellet elpee elper elren elten enent enete enlen ennet enper entel enten enter entre epeen epene ereen erept erere erlen ernen ernet ernle erpel erte ertel erter etern etete etnre etree ettel etten etter ettle leell leere leert lelep lelle lenne lente lepel leper lepet leppe lepre lept- leren lerer lerne leten letre lette n-p-n neele neere nelle nente neper neple neppe nepte neree neret nerre nerte neten netle netne nette nlnet ntete ntlet p-n-p p-rep peele peell peene peent peere peerl peert peete pelee peler pelet pelle pene- pener penne penre pent- pente pepee pepel peple peppe pept- perel peren perer peret perle perne pernt perre perte peter petr- petre pette pleen pleep pleet plene plete pllnt pptnt preen prell prelp prene prent prepl prepn prete prntr pter- ptere ptpre ptprn ptprr ptprt reene reepe reere relee relet relte renee rener renet renne rente repel repen repet reple reppe reprt rere- reree reret retee retel reter retnr rette rnpep rtenn teele teell teepe tele- telen telep teler tell- telle tenel tenen tener tenet tenne tenpn tente tepee tepet teret terne terre tert- tetel teten teter tetle tetr- tette tlell tlett tllnn tntnt tpler treen treer treet trele trene trent trepp trept trere trete trett ttnet ttttt