Maximise Sum

You are given an array $A$ of length $N$. You can perform the following operation on it any number of times (possibly, zero): - Choose any two distinct indices $i$ and $j$ ($1\leq i , j \leq N$ and $i \neq j$), and multiply both $A_i$ and $A_j$ by $-1$. That is, set $A_i$ to $-A_i$, and also $A_j$ to $-A_j$. Find the **maximum** possible sum of the array $A$ after performing this operation seve