Helsinki - Shanghai - Singapore - Shanghai (transit) - Helsinki

Greetings,

My itinerary is as follows

Helsinki - Shanghai (arrival 23rd Dec, 10 am)
Shanghai (departure 28th Dec 09 am) - Singapore
Singapore - Shanghai (arrival 2nd Jan, 05 am, transit 5 hours) - Helsinki

My question is as follows:

- Does Singapore count as the 3rd country in this case?
- Does 144 hour free transit apply to my itinerary if I am using Shanghai as a momentary transit point (i.e. I will be staying only inside Pudong airport transit premises while I am waiting for my next flight) on my way back to Helsinki from Singapore, or do I have to apply separately for a visa in this case?

Thank you in advance