Sell Upto 2

There are $N$ days, and the sell price of a watch on the $i$-th day is $A_i$. Initially you have $0$ watches. For each day from $1$ to $N$, the following events happen: - First, you acquire one watch for free on each day. - Next, you may choose to sell **upto $2$ watches** (that you own) for $A_i$ coins each. What is the maximum profit you can obtain by optimally selling items? ### Input - The