Far Away

Chef has an array $A$ of size $N$ and an integer $M$, such that $1 \leq A_i \leq M$ for every $1 \leq i \leq N$. The *distance* of an array $B$ from array $A$ is defined as: $$ d(A, B) = \sum_{i=1}^N |A_i - B_i| $$ Chef wants an array $B$ of size $N$, such that $1 \le B_i \le M$ and the value $d(A, B)$ is as large as possible, i.e, the distance of $B$ from $A$ is **maximum**. Find the **maximum