freon[9],
efor[8], neon[4], nero[4], orne[4], norn[4],
fen[7], nef[7], efo[7], fon[7], ref[7], for[7], orf[7], eon[3], one[3], non[3], ner[3], ren[3], ero[3], nor[3],
ef[6], fe[6], en[2], eo[2], no[2], on[2], er[2], re[2], or[2], ro[2],
