Determining the output sequence when using asyncio.gather

Which output will appear first in the console and why?

import asyncio

async def f1():
    await asyncio.sleep(1)
    print("f1")

async def f2():
    for _ in range(1_000_000_000):
        pass
    print("f2")

async def main():
    await asyncio.gather(f1(), f2())

asyncio.run(main())