Problem Statement

Oliver, who is British, is planning to build a shopping mall.

On floor $k\ (k \geq 0)$ of this shopping mall, there is space for at most $2^k$ shops.

Now, $n$ shops are going to move into this shopping mall, and $A_i$ staff members will come to the $i\ (1 \leq i \leq n)$-th shop.

Here, the cost of each shop is defined as follows.

• When the $i$-th shop is on floor $F_i\ (F_i \geq 0)$, its cost $C_i$ is $A_i \times F_i$

Oliver places the shops so that the total cost of all shops $\displaystyle \sum_{i=1}^{n} C_i$ is minimized.

Note that the floor numbering does not start from floor $1$.

Input

$n$
$A_1\ A_2\ \ldots \ A_n$

The first line contains the number of shops $n$.

The second line contains $A_1,\ A_2,\ \cdots ,\ A_n$ separated by spaces.

Constraints

• All inputs are integers
• $1 \leq n \leq 5 \times 10^4$
• $1 \leq A_i \leq 10^3$

Output

Output the minimum value of the total cost.
Print a newline at the end.

Sample

3
1 2 3

3

1
1

0

15
1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000

34000