Maximum Building I

• Time limit: 1.00 s
• Memory limit: 512 MB

You are given a map of a forest where some squares are empty and some squares have trees.

What is the maximum area of a rectangular building that can be placed in the forest so that no trees must be cut down?

Input

The first input line contains integers $n$ and $m$: the size of the forest.

After this, the forest is described. Each square is empty (.) or has trees (*).

Input

Print the maximum area of a rectangular building.

Constraints

• $1 \le n,m \le 1000$
  

Example

Input:
4 7
...*.*.
.*.....
.......
......*

Output:
12