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