문제
Bessie is building a fort with her friend Elsie. Like any good fort, this one needs to start with a sturdy frame. Bessie wants to build a frame in the shape of a one-meter-wide rectangular outline, atop which she will build the fort.
Bessie has already chosen a site on which to build the fort -- a piece of land measuring
Problem credits: Nathan Pinsker
입력
Line 1 contains integers
The next
출력
A single integer representing the maximum area that Bessie can cover with her fort.
예제1
5 6
......
..X..X
X..X..
......
..X...
16
In the example, the placement of the optimal frame is indicated by 'f's below:
.ffff.
.fX.fX
Xf.Xf.
.ffff.
..X...