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CSES Problem Set

Building


Task | Statistics


CSES - Building

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
Example

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


Output:
12