Pattern - Largest Rectangle in a Histogram

Time Limit : 1 sec, Memory Limit : 262144 KB
Japanese version is here

Largest Rectangle in a Histogram

A histogram is made of a number of contiguous bars, which have same width.

For a given histogram with $N$ bars which have a width of 1 and a height of $h_i$ = $h_1, h_2, ... , h_N$ respectively, find the area of the largest rectangular area.

Constraints

  • $1 \leq N \leq 10^5$
  • $0 \leq h_i \leq 10^9$

Input

The input is given in the following format.

$N$
$h_1$ $h_2$ ... $h_N$

Output

Print the area of the largest rectangle.

Sample Input 1

8
2 1 3 5 3 4 2 1

Sample Output 1

12

Sample Input 2

3
2 0 1

Sample Output 2

2