Given an array of n integers, arr[n] , rearrange them so that the following equation is minimized.

Note: The equation uses 1-based indexing.

Function Description

Complete the function findMinimumSum in the editor below.

findMinimumSum has the following parameters:

1. int arr[n] : the array to optimize

Returns

long: the minimum sum of products from the array

Example 1 :

Input: arr = [1, 10, 2, 7, 10, 6, 6]
Output: 127
Explanation:

One of the optimal rearrangements is arr = [10, 1, 7, 6, 6, 2, 10], producing the result 10 * 1 + 1 * 7 + 7 * 6 + 6 * 6 + 6 * 2 + 2 * 10 = 127.

Constraints: