There are four platforms at a railway station, each opening at different times: platform 1 at 5am, platform 2 at 6am, platform 3 at 7am, and platform ...

There are four platforms at a railway station, each opening at different times: platform 1 at 5am, platform 2 at 6am, platform 3 at 7am, and platform 4 at 8am. Trains arrive at these platforms one after another with a one-hour gap between arrivals on the same platform. Multiple trains can arrive on the same platform, but each arrival is spaced by one hour.

Given the following information:

1. Train M is not the only train arriving on its platform.
2. Train D arrives immediately before train B on the same platform.
3. There is a one-hour gap between the arrivals of train G and train H on the same platform.
4. No train arrives after train C, which arrives at 6am on one of the platforms.
5. Train G and train B arrive at the same time, with train B arriving on platform 1.
6. The train that arrives first at 5am on platform 1 also arrives at 7am on platform 3.
7. Train K arrives at platform 1 before train S, which arrives on platform 2.
8. Train H arrives at platform 2 at 7am.

Based on the above, which train arrives last on platform 1?