from itertools import zip_longest


class Polynomial:
    def __init__(self, *args):
        if len(args) == 0:
            args = (0,)
        self.coeffs = args

    def __repr__(self):
        return 'Polynomial{}'.format(repr(self.coeffs))

    def __str__(self):
        xs = ('{}*x^{}'.format(self.coeffs[i], i) for i in range(len(self.coeffs)))
        return ' + '.join(xs)

    def __len__(self):
        return len(self.coeffs) - 1

    def __add__(self, other):
        return Polynomial(*(x + y for x, y in zip_longest(self.coeffs, other.coeffs, fillvalue=0)))

    def __sub__(self, other):
        return Polynomial(*(x - y for x, y in zip_longest(self.coeffs, other.coeffs, fillvalue=0)))


def main():
    p1 = Polynomial(1, 2, 3)
    print(p1)
    print(len(p1))
    p2 = Polynomial(2, 3, 4, 5)
    print(repr(p2))
    print(p2)
    print(len(p2))
    print(p1 + p2)
    print(p1 - p2)
    p3 = Polynomial()
    print(repr(p3))
    p4 = Polynomial(0)
    print(p4)

if __name__ == '__main__':
    main()