You are almost on Semtex 3, there is just one big door before you. It is locked with a number lock. Analyze and use the locks in /semtex/semtex3 to adjust all the numbers in the correct way. They will open your way to the next level.
Tip : If you are not good at math, you should consider brute force. Rewrite the program and try all possible combinations of the locks. It wont take more than a few seconds ;)