bug[9], gub[9], buc[8], cug[8], buk[8], kub[8], kuc[7], bun[7], gnu[7], bru[7], bur[7], gur[7], rug[7], kun[6], cru[6], kur[6], nur[5], run[5], urn[5],
bu[6], gu[6], ku[5], nu[4],