UK Car Repair: double over head cam pulleys, vauxhall vectra, pullies

Question
Vauxhall Vectra LS 1.8 16valve p reg
I have taken a pulley off and it has a V shape where the locating pin goes and on it it has xn and in. the pulley that I am talking about is the front pully please can you tell me which way to put it on i.e xn or in.

Answer
hi ex stands for exhaust and in for inlet.
if you look at the engine from the wing the cam near the windscreen is the in side and the cam near the front of the car is the ex.
the cam pullies should be fitted depending on whitch side you are placing them.