Permutation Construction

You are given two integers $N$ and $X$. Your task is to construct a permutation $P$ of $\{1, 2, \ldots, N\}$ which satisfies the following conditions: - $P_1 = X$ - Let $D$ be the *difference array* of $P$, i.e, $D$ is an array of length $N-1$ such that $D_i = P_{i+1} - P_i$ for $1 \leq i \lt N$. The array $D$ should be a [palindrome](https://en.wikipedia.org/wiki/Palindrome). If there are mult