birrs[7],
sufi[7], rufs[7], surf[7], birr[6], bris[6], sirr[4], surr[4],
fis[6], ruf[6], brr[5], bis[5], bus[5], irr[3], sir[3], rus[3], sur[3], urs[3],
bi[4], si[2], ui[2], ur[2],