Given a list of points, which forms the exterior of a polygon, return a list of all points that are in the interior of the polygon. You are guaranteed the given points forms a single, connected polygon. The list of points is not in any particular order.

For example given: [(0,0), (0,1), (0,2), (1,0), (1,2), (2,0), (2,1), (2,2)]

return [(1,1)]