def multiply(a, b):
    """Returns the product of two numbers."""
    return a * b


def subtract(a, b):
    """Returns the difference between two numbers."""
    return a - b


def add(a, b):
    """Returns the sum of two numbers."""
    return a + b


class Point:
    def move(self, dx, dy):
        """Moves the point by a given distance along x and y axes."""
        self.x += dx
        self.y += dy

    def __init__(self, x=0, y=0):
        """Initializes a point with coordinates (x, y)."""
        self.x = x
        self.y = y

    def distance_to_origin(self):
        """Returns the distance from the point to the origin."""
        return (self.x**2 + self.y**2) ** 0.5