I assume that this is with prep. I'd bring multiple pairs of shoes, a handgun, a spear, heavy clothes made of leather, a pickaxe, and a ski mask. I'd noclip in, break the floor, end up in 27, carefully make my way without disturbing the entities there, end up in Level 4, skip levels 5-8 using the pickaxe to exploit a loophole, and end up in Level 9. This would be my biggest obstacle, This is why I brought a gun and spear. It would be a fairly long journey, but I would soon make it to Level 11. Once I was there, I'd look around until I found an office, go in there, and end up in Level 3999. From there, I'd escape.