echa[7], heca[7], anch[7], chan[7], chna[7], chen[7], henn[6], cena[5],
ach[6], cha[6], che[6], ech[6], hec[6], han[5], hen[5], cna[4], cen[4], cne[4],
ha[4], eh[4], he[4], ce[3], na[2], en[2],
