Pattern of the Drunk

Kabir has a very bad habit of alcohol. He drinks a lot, his friends tried to stop him but he got angry and left the home. While he was walking and drinking down the road, he entered into a hotel with N rooms. Since, kabir was too drunk, he started to open and close the door in a weird pattern. Say the doors are numbered from *1* to *N*, with the leftmost door numbered 1. If a door is opened, h