pfe[8], fen[7], nef[7], che[6], ech[6], hec[6], hep[6], ben[5], hen[5], cep[5], cen[4], cne[4], nep[4], pen[4],
ef[6], fe[6], be[4], eh[4], he[4], ce[3], pe[3], en[2],
