Don't Panic, read on.
Step 1: How to Sneak in a V-Belt
I've seen this configuration on cars by Geo, Volvo, Mercedes that have the engine in a fore-aft direction. It shows the belts and pulleys as you might see them looking through the radiator towards the engine and everything behind it.
Step 2: You can't get there from here
You can slacken the alternator tensioner to get belt A off of the alternator and the water pump, or just cut it if it isn't gone already.