### Problem Statement

We want to buy a rectangular plot on a rectangular vegetable field. We want our plot to be as big as possible, but we only have the resources to grow a maximum of 2 different kinds of vegetables on it. You are given a String[] field, where each character represents a square in the field. All squares are of equal size. The j-th character of the i-th element of field denotes the kind of vegetable that grows in the square at row i, column j - it's an uppercase letter ('A' - 'Z'), where each letter denotes a different kind of vegetable. Return the area of the biggest plot we can buy.

### Definition

 Class: VegetableField Method: biggestPlot Parameters: String[] Returns: int Method signature: int biggestPlot(String[] field) (be sure your method is public)

### Constraints

-field will contain between 2 and 20 elements, inclusive.
-Each element of field will contain between 2 and 20 characters, inclusive.
-All elements of field will contain the same number of characters.
-Each character in each element of field will be an uppercase letter ('A' - 'Z').

### Examples

0)

 ```{ "AAA", "AAA", "AAA" }```
`Returns: 9`
 Only one type of vegetable grows here so we can buy the whole field.
1)

 ```{ "ABCDEFGH", "IJKLMNOP", "QRSTUVWX" }```
`Returns: 2`
2)

 ```{ "AAAA", "ABBC", "BBCA", "DCAA" }```
`Returns: 6`
3)

 ```{ "AUFLKNCSLKX", "OWVGWXGHKFB", "MUFZEELAWOR", "CZCGHXVGWDW", "EPNSDSJSKWT", "APULZGHXMEK", "UVMQQUFMYYQ", "XWLMVXKSENF", "KGZJUDQOAXA", "UKIBGOSXSZL" }```
`Returns: 4`
4)

 ```{ "BDCDCCCCBED", "ECEAADCEACA", "AABEABBACBB", "CEBEDDDDBDE", "DBCACCABBDE", "CCEECDCECBB", "CCADACEDDCE", "DDCEAACAEBB", "CACCEEAACCA", "DBAACCEEACD", "DDBAACBEEAE" }```
`Returns: 8`

#### Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=8059

#### Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=10774&pm=8059

mateuszek

#### Testers:

PabloGilberto , brett1479 , Olexiy , ivan_metelsky

#### Problem categories:

Brute Force, Simple Search, Iteration