birg[7], burg[7], grub[7], bugs[7], ibis[6], bris[6], giri[5], urig[5], grus[5], iris[4],
gib[6], bug[6], bis[5], bus[5], gis[4], gur[4], sir[3], rus[3], sur[3], urs[3],
bi[4], si[2], ui[2], ur[2],
