### Problem Statement

John and Brus are bored. They have n+m common friends. The first n of them are bored and other m are not. John chooses the j-th (1-based) friend for a talk. If the friend is not bored, he becomes bored after the talk. Brus does the same with the b-th (1-based) friend. Note that John and Brus can't choose the same friend.

You have to find the number of bored friends after the talks.

### Definition

 Class: TheBoredomDivTwo Method: find Parameters: int, int, int, int Returns: int Method signature: int find(int n, int m, int j, int b) (be sure your method is public)

### Constraints

-n will be between 1 and 47, inclusive.
-m will be between 1 and 47, inclusive.
-j will be between 1 and n+m, inclusive.
-b will be between 1 and n+m, inclusive.
-j and b will be different.

### Examples

0)

 `1` `1` `1` `2`
`Returns: 2`
 The first friend is already bored and the second friend becomes bored after the talk with Brus.
1)

 `2` `1` `1` `2`
`Returns: 2`
 Here John and Brus choose two friends that are already bored.
2)

 `1` `2` `3` `2`
`Returns: 3`
 All the friends become bored.
3)

 `4` `7` `7` `4`
`Returns: 5`

#### Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=11194

#### Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=14241&pm=11194

Vasyl[alphacom]

#### Testers:

PabloGilberto , ivan_metelsky , nika