import math


def distance(a, b):
    """
    Return the distance between two vectors

    Example:

    >>> a = Vector(0, 0)
    >>> b = Vector(1, 0)
    >>> c = Vector(1, 1)
    >>> print(distance(a, b), distance(a, c))
    1.0 1.4142135623730951
    """
    return math.sqrt((a.x - b.x) ** 2 + (a.y - b.y) ** 2)