You are given an array maximumHeight, where maximumHeight[i] denotes the maximum height the ith tower can be assigned.

Your task is to assign a height to each tower so that:

  1. The height of the ith tower is a positive integer and does not exceed maximumHeight[i].
  2. No two towers have the same height.

Return the maximum possible total sum of the tower heights. If it's not possible to assign heights, return -1.

 

Example 1:

Input: maximumHeight = [2,3,4,3]

Output: 10

Explanation:

We can assign heights in the following way: [1, 2, 4, 3].

Example 2:

Input: maximumHeight = [15,10]

Output: 25

Explanation:

We can assign heights in the following way: [15, 10].

Example 3:

Input: maximumHeight = [2,2,1]

Output: -1

Explanation:

It's impossible to assign positive heights to each index so that no two towers have the same height.

 

Constraints: