from math import sqrt

class Vector:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def __bool__(self):
        return bool(self.x) or bool(self.y)

    def __truediv__(self, divisor):
        return Vector(self.x / divisor, self.y / divisor)

    def __floordiv__(self, divisor):
        return Vector(int(self.x / divisor), int(self.y / divisor))

    def __add__(self, other):
        return Vector(self.x + other.x, self.y + other.y)

    def __sub__(self, other):
        return Vector(self.x - other.x, self.y - other.y)

    def __neg__(self):
        return Vector(-self.x, -self.y)

    def __invert__(self):
        return Vector(self.y, self.x)

    def __str__(self):
        return "(%d, %d)" % (self.x, self.y)

    def __abs__(self):
        return sqrt(self.x * self.x + self.y * self.y)

def hilbert(center, x, y):
    if abs(x) < 1:
        print(center)
    else:
        x /= 2
        y /= 2
        hilbert(center - x + y, -~x, -~y)
        hilbert(center - x - y,   x,   y)
        hilbert(center + x - y,   x,   y)
        hilbert(center + x + y,  ~x,  ~y)


def hilbertgenerator(center, x, y):
    if abs(x) < 1:
        yield center
    else:
        x /= 2
        y /= 2
        for r in hilbertgenerator(center - x + y, -~x, -~y):
            yield r
        for r in hilbertgenerator(center - x - y,   x,   y):
            yield r
        for r in hilbertgenerator(center + x - y,   x,   y):
            yield r
        for r in hilbertgenerator(center + x + y,  ~x,  ~y):
            yield r