9.2 Imagine a robot sitting on the upper left comer of an X by Ygrid. The robot can only move in two directions: right and down. How many possible paths are there for the
robot to go from (0, 0) to (X, Y) ?
Imagine certain spots are "off limits," such that the robot cannot step on them.
Design an algorithm to find a path for the robot from the top left to the bottom right.