dero[5], oder[5], rode[5], euro[5], roue[5], drud[4], urdu[4],
deo[4], ode[4], rod[4], duo[4], der[3], erd[3], red[3], dur[3], reu[3], ure[3],
do[3], od[3], er[2], re[2], du[2], ud[2], ur[2],
