 For each subset formula_16, it computes the convex hull, formula_17, using an formula_18 algorithm (for example, Graham scan), where formula_19 is the number of points in the subset.As there are formula_20 subsets of formula_21 points each, this phase takes formula_22 time.During the second phase, Jarvis's march is executed, making use of the precomputed (mini) convex hulls, formula_23.