Given a string s, you can perform the following operation any number of times:

$1$. Select an index i in s, and let c be the character at s[i].
$2$. Remove the closest occurrence of c to the left of i, if one exists.
$3$. Remove the closest occurrence of c to the right of i, if one exists.

Return the minimum possible length of s after performing any number of operations.

Constraints:

• $1 \leq$ s.length $\leq 100$

• s contains only lowercase English letters

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.