### Problem Statement

A boot shop has received a shipment from the factory consisting of N left boots and N right boots. Each boot has some integer size, and a left and right boot will form a proper pair if they have equal sizes. Each boot can only belong to a single pair. The employees of the boot store want to create N proper pairs of boots. Fortunately, the factory has offered to exchange any number of boots in the shipment with new boots of different sizes.

You are given a int[] left and a int[] right containing the sizes of the left boots and right boots, respectively. Return the least number of boots that must be exchanged.

### Definition

 Class: BootsExchange Method: leastAmount Parameters: int[], int[] Returns: int Method signature: int leastAmount(int[] left, int[] right) (be sure your method is public)

### Constraints

-Each element in left will be between 1 and 1000, inclusive.
-Each element in right will be between 1 and 1000, inclusive.
-left and right will have the same number of elements.
-left will contain between 1 and 50 elements, inclusive.

### Examples

0)

 `{1, 3, 1}` `{2, 1, 3}`
`Returns: 1`
 They can exchange a size 1 left shoe for a size 2 left shoe, or they can exchange the size 2 right shoe for a size 1 right shoe.
1)

 `{1, 3}` `{2, 2}`
`Returns: 2`
 They can exchange both left shoes for size 2 left shoes, or they can exchange the right shoes for a size 1 right shoe and a size 3 right shoe, or they can mix these two possibilities.
2)

 `{1, 2, 3, 4, 5, 6, 7}` `{2, 4, 6, 1, 3, 7, 5}`
`Returns: 0`
 Nothing to exchange.

#### Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=6081

#### Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=9987&pm=6081

Mike Mirzayanov

#### Testers:

PabloGilberto , brett1479 , Olexiy , marian

Greedy