Charger duckhead help please.

Hi all, I have two Macbook Pro's, a 2021 with a 140w US USB-C charger and a 2015 with an 85w US Magsafe 2 charger. I've mixed up the duckhead adapters (the cube shaped, two prong part that plugs directly into the wall) one is 125v - 2.5amp (model A1555 M), and the other is 125v - 7amp (model A1555 P). Anyone happen to know which goes to which charger? Thanks in advance for any assistance.