def remember_sum_ineff(L, s):
  if L == []:
    return s
  else:
    return remember_sum(L[1:], s+L[0])
def sum_all_ineff(L):
  return remember_sum(L,0)



def remember_sum(L, s,pos):
  if pos >= len(L):
    return s
  else:
    return remember_sum(L, s+L[pos],pos+1)
def sum_all(L):
  return remember_sum(L,0,0)