## CWB - Chipmunks with Brain

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There is a Chipmunk with "Brain" and he want to dig holes in a yard to store his food.
There is a rectangular yard which is divided into unit cells, initially having some holes(H) and sand(S). The chipmunk can dig one row at a time, But he have to dig all the sand(S) positions simultanously and due to this holes(H) which are already there got filled with sand.

Example:
Suppose a Row is "SHSHH" then after digging the row becomes "HSHSS" i.e all "S" replace with "H" and vice versa.

Now Chipmunk wants to have a large square of holes somewhere in the yard. The sides of square must be parallel to the sides of the yard. Find a sequence of turns that produces the largest possible square of holes somewhere in the yard and help him to find the area of that square.

### Input

Given two interger Rows(R) and column(C) (1<=R,C<=30)
Next line contain a RxC rectangular yard of sand (S) and hole (H).

### Output

Print largest "Area of the Square" that can be obtain after sequence of turns.

### Example

```Input:
2 2SSHH
Output:
4Input:
5 1HSHHH
Output:
1```