Dubai Micro Mystery Mystery Cache

Dubai Micro Mystery

This is a cache for people don't having much time, e.g. because of a connecting flight. You should to be free approx. two hours at the minimum.

Now Your job to find the cache:
Find out the IATA-Code of Dubai International Airport. If You don't know the code, ask someone at the check in counter or at the information desk. Or You have a look at Your baggage or ticket!

Change the letters from the code in numbers as follows:
A=1, B=2, C=3…
and make an algebraic sum of the figures. This is "Z"
The second letter respectively figure of the code is "X"

Final:

N(Header) + (X-Z)*X+144
E(Header) - {[(Z+X)*Z/X]*2-135}