fier[7], frei[7], reif[7], rief[7], bier[6], brei[6], brie[6], reib[6], rieb[6], birr[6], irre[4],
fei[6], bei[5], erb[5], brr[5], ire[3], irr[3],
bi[4], ei[2], er[2], re[2],