  In [J.Birman, V.Gebhardt, J.Gonzalez-Meneses, Conjugacy in Garside groups I:
cyclings, powers and rigidity] authors asked: (open question 2) is the size of
USS of a rigid pseudo-Anosov braid is bounded above by some polynomial in the
number of strands and the braid length? We answer this question in the
negative.
