I'm not sure if you're saying that you don't understand how the codes work or that you can't find the code for the cupboard, so I'll explain both:
- X and Y are referring to the numbers that the "codes" have.
For example, in "9 with 3", X = 9 and Y = 3.
And what that means is that "you need to input 3 distinct numbers that add to 9".
- If you can't find the file with the code, maybe you should try powering on the computer on the desk. But you will need something from the storage room to do so.