'Returns the degree of the polynomial.
Examples:
>>> BitPolynom(0).degree()
0
>>> BitPolynom(1).degree()
0
>>> BitPolynom(2).degree()
1
>>> BitPolynom(7).degree()
2
>>> BitPolynom((1 << 10) - 1).degree()
9
>>> BitPolynom(1 << 10).degree()
10'

def degree(self):

    return max(0, (int(self).bit_length() - 1))
