class consume:
    STOP = object()

    def __init__(self, next_val, consumed, used_cnt):
        self.start = True
        self.next_val = next_val
        self.consumed = consumed
        self.used_cnt = used_cnt
        self.loop = asyncio.get_event_loop()

    def __aiter__(self):
        return self

    async def __anext__(self):
        if not self.start:
            self.used_cnt[0] -= 1
            if not self.used_cnt[0]:
                self.consumed[0].set_result(None)
                self.consumed[0] = self.loop.create_future()
                self.next_val[0] = self.loop.create_future()
                self.used_cnt[0] = 2
            else:
                await self.consumed[0]
        else:
            self.start = False

        val = await self.next_val[0]
        if val is consume.STOP:
            raise StopAsyncIteration
        return val


async def max_and_sum_asyncio(it):
    loop = asyncio.get_event_loop()

    next_val = [loop.create_future()]
    consumed = [loop.create_future()]
    used_cnt = [2]

    async def produce():
        for elem in it:
            next_val[0].set_result(elem)
            await consumed[0]
        next_val[0].set_result(consume.STOP)

    produce_task = loop.create_task(produce())
    s, m = await asyncio.gather(asum(consume(next_val, consumed, used_cnt)), amax(consume(next_val, consumed, used_cnt)))
    await produce_task

    return s, m