class Stueue():

    def __init__(self):
        self._contents = []
        self._dequeue_top = True

    def put(self, item):
        self._contents.insert(0, item)

    def get(self):
        ret = None
        if not self.isempty():
            if self._dequeue_top:
                ret = self._contents.pop(0)
            else:
                ret = self._contents.pop(-1)
        self._dequeue_top = not self._dequeue_top
        return ret

    def peek(self):
        ret = None
        if not self.isempty():
            if self._dequeue_top:
                ret = self._contents[0]
            else:
                ret = self._contents[-1]
        return ret

    def is_empty(self):
        return(self._contents == [])

    def copy(self):
        su = Stueue()
        su._contents = self._contents
        su._dequeue_top = self._dequeue_top
        return su