How to Solve Find Polygon With the Largest Perimeter Problem

You are given an array of positive integers nums of length n. A polygon is a closed plane figure that has at least 3 sides. The longest side of a polygon is smaller than the sum of its other sides. Conversely, if you have k (k >= 3) positive real numbers a1, a2, a3, ..., ak where a1 <= a2 <= a3 <= ... <= ak and a1 + a2 + a3 + ... + ak-1 > ak, then there always exists a polygon with k sides whose lengths are a1, a2, a3, ..., ak. The perimeter of a polygon is the sum of lengths of its sides. Return the largest possible perimeter of a polygon whose sides can be formed from nums, or -1 if it is not possible to create a polygon.