You are given nums, an array of positive integers of size 2 * n. You must perform n operations on this array. In the ith operation (1-indexed), you will: Choose two elements, x and y. Receive a score of i * gcd(x, y). Remove x and y from nums. Return the maximum score you can receive after performing n operations. The function gcd(x, y) is the greatest common divisor of x and y. Example 1: Input: nums = [1,2] Output: 1 Explanation: The optimal choice of operations is: (1 * gcd(1, 2)) = 1 Example 2: Input: nums = [3,4,6,8] Output: 11 Explanation: The optimal choice of operations is: (1 * gcd(3, 6)) + (2 * gcd(4, 8)) = 3 + 8 = 11 Example 3: Input: nums = [1,2,3,4,5,6] Output: 14 Explanation: The optimal choice of operations is: (1 * gcd(1, 5)) + (2 * gcd(2, 4)) + (3 * gcd(3, 6)) = 1 + 4 + 9 = 14 Constraints: 1 <= n <= 7 nums.length == 2 * n 1 <= nums[i] <= 106