You are given an integer array nums.

The concatenation of two numbers is the integer obtained by joining their digits together. For instance, the concatenation of $15$ and $49$ is $1549$.

The array concatenation value is initially $0$. Execute the following process until nums becomes empty:

• If there are at least $2$ elements in nums, pick the first element and the last element, concatenate their values, add the resulting number to the array concatenation value, and remove both elements from nums.

• If there is only $1$ element remaining in nums, add its value to the array concatenation value and remove it from nums.

Return the final concatenation value of nums.

Constraints:

• $1 \leq$ nums.length $\leq 1000$

• $1 \leq$ nums[i] $\leq 10^4$

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.