import asyncio
import time

async def say_after(delay, what):
    print(1)
    await asyncio.sleep(delay)
    print(what)
    
async def say_after2(delay, what):
    print(2)
    await asyncio.sleep(delay)
    print(what)

async def say_after3(delay, what):
    print(3)
    await asyncio.sleep(delay)
    print(what)
    

async def main():
    l = []
    
    await say_after3(3, "delay1")
    
    task1 = asyncio.create_task(
        say_after(1, 'hello'))

    task2 = asyncio.create_task(
        say_after2(2, 'world'))
    
    l.append(task1)
    l.append(task2)
    
    task1.add_done_callback(l.remove)
    task2.add_done_callback(l.remove)
    
    
    await say_after3(3, "delay2")

    print(f"started at {time.strftime('%X')}")

    # Wait until both tasks are completed (should take
    # around 2 seconds.)
    # await task1   
    # await task2
    
    while len(l) != 0:
        print("wait...")
        await asyncio.sleep(1)

    print(f"finished at {time.strftime('%X')}")
    
    
if __name__ == "__main__":
    asyncio.run(main())