Can we profit from the Visa Free Transit?

Hello there,

My situation is:
We are flying to Beijing from Ulan Ude (Russia) on the 3rd of Jan. 2018 and leaving to Europe on the 6th Jan. 2018, my final destination is Warsaw and my friend's is Paris, our flight back has a scale in Kiev - Ukraine.
The gap between our flights is less than 72 hours and my friend and I are both Brazilian citizens.