You are given a positive integer array skill of even length $n$, where skill[i] represents the skill level of the $i^{ ext{th}}$ player.

Divide the players into $n / 2$ teams of size $2$ such that the total skill of each team is equal.

The chemistry of a team is equal to the product of the skills of the two players on that team.

Return the sum of the chemistry of all teams, or return $-1$ if it is impossible to divide the players into teams such that each team has equal total skill.

Constraints:

• $2 \leq$ skill.length $\leq 10^5$

• skill.length is even.

• $1 \leq$ skill[i] $\leq 1000$

Now, let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Implement your solution in the following coding playground.