def __find_smallest(self):
        """Find the smallest uncovered value in the matrix."""
        minval = 2e9  # sys.maxint
        for i in range(self.n):
            for j in range(self.n):
                if (not self.row_covered[i]) and (not self.col_covered[j]):
                    if minval > self.C[i][j]:
                        minval = self.C[i][j]
        return minval
Find the smallest uncovered value in the matrix.
ppdet/metrics/munkres.py