-ene -one eeee eero enee eneo ener enne eno- enoe enon enp- eone eore epee epen eper epon epor epox eppo eppp epro eprp epxp er-x eren erer erne erno eroe eron eroo erpe erre erro exen exer exo- exon exor expn expo expr exrx neen neep neer nene neno neo- neon neoo neox nepe nepr nere nero nerr nexe nexo nexx nnnn nnpr noer non- none nonn nono nonx noo- noon nooo noop noor nope nor- nore norn noro norr nren nron nrpn o-eo oen- oeno oere one- onee oneo onep oner onex onne onno onon onor ooer oone oooo oore open opep oper opex opo- opon opor oppo ore- oren oreo orer orex orne orno oro- oroe oron oror orpe orro oxen oxep oxer oxo- oxon oxox oxxo peen peep peer pen- pene penn peno peon peor pepe pepo per- pere pern pero perp perr pnon pnpo pnpp pnro poer pone pono ponp poon poop poor pop- pope popo popp pore porn poro porr ppen pper pppn pppo pppp pre- pree pren prep prex prnp pro- proe pron proo prop prox reen reep rene renn reno reop repe repo repp repr rere rero rexx roen roer rone rono roon roop roor roox rope ropo rore roro roxo rpoe rpon rppn rrrr xeer xen- xene xenn xeno xeon xer- xero xexe xnee xorn xoro xorp xoxo xper xrep xxxo xxxx