Ghost and angels

Dexter is stuck in a maze. It consists of 100 rooms, where each of the $i^{th}$ room is connected to $(i+1)^{th}$ room. There are 3 types of rooms - room with angel, room with ghost, empty room. Dexter wants to get out of the maze as fast as possible by reaching the room number 100. He wants to escape in the minimum number of turns. In one turn Dexter can move $X$ number of rooms ahead where $1 \l