from math import sqrt
class Vector(object):
    """docstring for Vector"""
    def __init__(self,x,y):
        self.x=x
        self.y=y
    def dlina (self):
        return sqrt ( self.x * self.x + self.y * self.y)
    def dl2 (self):
        return self.x * self.x + self.y * self.y
    def __add__ (self, other):
        return Vector(self.x + other.x, self.y + other.y)
    def __repr__ (self):
        return "Vector : " + str(self.x) + " " + str(self.y)
    def dot (self, other):
        return self.x * other.x + self.y * other.y
    def __mul__ (self, c):
        return Vector(self.x * c, self.y * c)
    def __rmul__ (self, c):
        return self * c
    def __div__ (self, c):
        return Vector(self.x / float(c), self.y / float(c))
    def eye(self):
        return self / self.dlina()
    def perp(self):
        return Vector(-self.y, self.x)


print __name__
def main():
    a = Vector(1,2)
    b = Vector(3,4)
    c = a + b
    print c.dot(a)
    print c
    d = a * 3
    print d
    d = 3 * a
    print d / 3
    g = Vector(1, 5)
    print g.eye()
    g1=g.perp()
    print g1.eye()

if __name__ == "__main__":
    main()