In the divide-and-conquer hull algorithm, we learned how to find the upper tangent and the lower tangent of two disjoint convex polygons. There are four possible tangents between two disjoint convex polygons. A cross-tangent line that has one polygon below it and the other one above it. Let A and B be disjoint convex polygons, each with n vertices. Describe an O(n) time algorithm to find one of the cross-tangents of A and B.