class Stack:
  """a stack is a LIFO data structure where the last item put in is the first item taken out"""
  def __init__(self):
    self.items = []

  def push(self, item):
    """adds a new item to the stack"""
    return self.items.append(item)

  def pop(self):
    """removes the last item from the stack"""
    return self.items.pop()

  def size(self):
  """returns the size of stack"""
  return len(self.items)


orders = [(1, "221 Baker Street"), (2, "700 Parker Street"), (3, "2200 High Street"), (4, "642 Andover Way")]
reversed_orders = []
stack = Stack()

for i in orders:
  stack.push(i)

for i in range(stack.size()):
  reversed_orders.append(stack.pop())

for order in reversed_orders:
  print(f"Order number {order[0]} was delivered to {order[1]}.") # fstrings require Python 3.6, fyi