You are given an integer array stones where stones[i] represents the number of stones in the $i^{ ext{th}}$ pile, arranged in a row. You are also given an integer k.

In each operation, you can choose exactly k consecutive piles and merge them into a single pile. The cost of this operation is the sum of the stones in those k piles.

Return the minimum cost to merge all piles into one single pile. If it is impossible to merge all piles into one pile, return $-1$.

Constraints:

• n $==$ stones.length

• $1 \leq$ n $\leq 30$

• $1 \leq$ stones[i] $\leq 100$

• $2 \leq$ k $\leq 30$

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.