### Problem Statement

In a set of distinct numbers, the median is an element M such that the number of elements greater than M is equal to the number of elements smaller than M. For example, in a set {1, 4, 2, 5, 7} the median is 4 because two elements (5 and 7) are greater than 4 and 2 elements (1 and 2) smaller than 4. The set {1, 5, 8, 3} has no median because no element from it satisfies the definition above.

You are given a int[] numbers. Return the median of numbers or -1 if numbers has no median.

### Definition

 Class: MedianOfNumbers Method: findMedian Parameters: int[] Returns: int Method signature: int findMedian(int[] numbers) (be sure your method is public)

### Constraints

-numbers will contain between 1 and 50 elements, inclusive.
-Each element of numbers will be between 1 and 100, inclusive.
-All elements of numbers will be distinct.

### Examples

0)

 `{1, 4, 2, 5, 7}`
`Returns: 4`
 The example from the statement.
1)

 `{1, 5, 8, 3}`
`Returns: -1`
2)

 `{7}`
`Returns: 7`
 There are zero elements that are greater than 7 and zero elements that are smaller than 7.
3)

 `{7, 12}`
`Returns: -1`
4)

 `{66, 53, 47, 86, 18, 21, 97, 92, 15}`
`Returns: 53`
5)

 `{32, 54, 27, 4, 69, 96, 73, 1, 100, 15, 21}`
`Returns: 32`

#### Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=6528

#### Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=9988&pm=6528

Andrew_Lazarev

#### Testers:

PabloGilberto , brett1479 , vorthys , Olexiy

Simple Math