Heat Exchanger A3 8L: Supply & Return

Can someone tell me which of the two hoses connected to the heat exchanger is the inlet and which is the outlet?
I'm always surprised by that.
They are next to each other; I can also take a picture if you'd like.
Thank you.

There are 2 possibilities:

- using standard hose clamps
----> Supply line to the water tank on the driver's side.
- with quick-connect fitting; supply line to the water tank on the passenger side.

You're welcome.
For me, they are clamp connectors.