I'm in a weird situation. I need to find a file based on its contents, not the name because the name is not unique...

For example, I have a file named "cat.jpg". It is a picture of a cat. I happen to have 5 million copies of that in 5 million different folders, so, while the folder names are different, the file names are the same:

```
cat1/cat.jpg
cat2/cat.jpg
cat3/cat.jpg
etc...

```

However, one of those cat.jpgs is actually a picture of a dog (and the file is still named "cat.jpg")

How can I find the one that is a dog assuming I have an exact copy of it available. I can't do filename search because then I'll just get 5 million results of "cat.jpg"