Make Palindrome 2

You are given a binary string $S$ of length $N$. You want to obtain a [palindrome](https://en.wikipedia.org/wiki/Palindrome) from $S$ by applying the following operation **at most** $\left\lfloor \frac{N}{2} \right\rfloor$ times: - Choose an index $i\;(1 \le i \le \lvert S \rvert)$, delete the character $S_i$ from $S$ and concatenate the remaining parts of the string. Here $\lvert S \rvert$ denot