IN PYTHON-Suppose that you leave your dog in the middle of a large city whose streets form a familiar grid pattern. We assume that there are n northsouth streets and n eastwest streets, all regularly spaced and fully intersecting in a pattern known as a lattice. Trying to escape the city, the dog makes a random choice of which way to go at each intersection, but knows by scent to avoid visiting any place previously visited. But it is possible for the dog to get stuck in a dead end where there is no choice but to revisit some intersection. What is the chance that this will happen?