Multiple times, my cat has managed hit a key combination on my desktop that swaps WASD and the arrow keys, which I never knew existed before the first time she

Multiple times, my cat has managed hit a key combination on my desktop that swaps WASD and the arrow keys, which I never knew existed before the first time she did it. I think it's something like Fn+w, but every time it's happened I always forget exactly what it is, and it takes a bit of effort to search for it because I need to actually use the arrow keys to type those letters, which are a pretty important part of the query...