  We present a subset method which solves the sign problem for QCD at nonzero
quark chemical potential in 0+1 dimensions. The subsets gather gauge
configurations based on the center symmetry of the SU(3) group. We show that
the sign problem is solved for one to five quark flavors and that it slowly
reappears for a larger number of flavors. We formulate an extension of the
center subsets that solves the sign problem for a larger number of flavors as
well. We also derive some new analytical results for this toy model.
