**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