Problem9935--ABC311 —— G - One More Grid Task

9935: ABC311 —— G - One More Grid Task

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Time Limit : 1.000 sec  Memory Limit : 512 MiB

Description

There is an $N \times M$ grid, where the square at the $i$-th row from the top and $j$-th column from the left has a non-negative integer $A_{i,j}$ written on it.  
Let us choose a rectangular region $R$.  
Formally, the region is chosen as follows.

-   Choose integers $l_x, r_x, l_y, r_y$ such that $1 \le l_x \le r_x \le N, 1 \le l_y \le r_y \le M$.
-   Then, square $(i,j)$ is in $R$ if and only if $l_x \le i \le r_x$ and $l_y \le j \le r_y$.

Find the maximum possible value of $f(R) = $ (the sum of integers written on the squares in $R$) $\times$ (the smallest integer written on a square in $R$).

Input

The input is given from Standard Input in the following format:

```
$N$ $M$
$A_{1,1}$ $A_{1,2}$ $\dots$ $A_{1,M}$
$A_{2,1}$ $A_{2,2}$ $\dots$ $A_{2,M}$
$\vdots$
$A_{N,1}$ $A_{N,2}$ $\dots$ $A_{N,M}$
```

Output

Print the answer as an integer.

Constraints

-   All input values are integers.
-   $1 \le N,M \le 300$
-   $1 \le A_{i,j} \le 300$

Sample 1 Input

3 3
5 4 3
4 3 2
3 2 1

Sample 1 Output

48
Choosing the rectangular region whose top-left corner is square (1,1) and whose bottom-right corner is square (2,2) achieves f(R)=(5+4+4+3)×min(5,4,4,3)=48, which is the maximum possible value.

Sample 2 Input

4 5
3 1 4 1 5
9 2 6 5 3
5 8 9 7 9
3 2 3 8 4

Sample 2 Output

231

Sample 3 Input

6 6
1 300 300 300 300 300
300 1 300 300 300 300
300 300 1 300 300 300
300 300 300 1 300 300
300 300 300 300 1 300
300 300 300 300 300 1

Sample 3 Output

810000

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