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.
The input is given in the following format.
$N$
$h_1$ $h_2$ ... $h_N$
Print the area of the largest rectangle.
8 2 1 3 5 3 4 2 1
12
3 2 0 1
2