# 0603.py

class vettore:
  def __init__(A,x,y,z):
    A.x=float(x); A.y=float(y); A.z=float(z)
  def __add__(A,B): return vettore(A.x+B.x,A.y+B.y,A.z+B.z)
  def __mul__(A,t): return vettore(A.x*t,A.y*t,A.z*t)
  def __rmul__(A,t): return A*t
  def coeff(A): return [A.x,A.y,A.z]
  def ps (A,B): return A.x*B.x+A.y*B.y+A.z*B.z
  def pv (A,B):
    (x,y,z)=A.coeff(); (u,v,w)=B.coeff()
    return vettore(y*w-z*v,z*u-x*w,x*v-y*u)

#######################################

a=vettore(2,3,5)
b=vettore(1,7,2)

c=a+b
print (c.coeff())
# [3.0, 10.0, 7.0]

c=a.__add__(b)
print (c.coeff())
# [3.0, 10.0, 7.0]

#######################################

a=vettore(2,3,5)
b=a*4
print (b.coeff())
# [8.0, 12.0, 20.0]

#######################################

a=vettore(2,3,5); b=vettore(1,7,2)

print (a.ps(b))
# 33.0

print (a.pv(b).coeff())
# [-29.0, 1.0, 11.0]