K Subsequence 101

Let $B$ be an array of size $M \ (M \ge 2)$. We define $f(B)$ as $\displaystyle{\sum_{i = 1}^{M - 1} (B_i + B_{i + 1})}$. You are given an array $A$ of size $N$, and an integer $K$. Find the maximum value of $f(C)$ where $C$ denotes a $K$-sized [subsequence](https://en.wikipedia.org/wiki/Subsequence) of array $A$. ### Input - The first line of input will contain a single integer $T$, denoting