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CSES Problem Set

 Time limit: 1.00 s Memory limit: 512 MB

A fence consists of $n$ vertical boards. The width of each board is 1 and their heights may vary.

You want to attach a rectangular advertisement to the fence. What is the maximum are of such an advertisement?

Input

The first input line contains an integer $n$: the width of the fence.

After this, there are $n$ integers $k_1,k_2,\ldots,k_n$: the height of each board.

Output

Print one integer: the maximum area of an advertisement.

Constraints
• $1 \le n \le 5 \cdot 10^5$
• $1 \le k_i \le 10^9$
Example

Input:
8 4 1 5 3 3 2 4 1

Output:
10