# 0607.py

class lista:
  def __init__(A,*v): A.elementi=v
  def __lshift__(A,n): return A.elementi[n]
  def __pos__(A):
    s=0
    for x in A.elementi: s+=x
    return s

a=lista(3,5,9,6,4)
print (a<<2, +a)
# 9 27

class cerchio:
  def __add__(A,B): print ('***')
  def __pos__(A): print ('Ciao.')

u=cerchio()
u+u
# ***
+u
# Ciao.