### Problem Statement

A column diagram is composed of n consecutive columns arranged in a horizontal row. Each column has a width of 1, and the base of each column is on the x-axis. The heights of the columns are given in the int[] a, where a[i] is the height of the i-th column. The picture below shows an example of a column diagram: Return the perimeter of the given column diagram.

### Definition

 Class: ColumnDiagramPerimeter Method: getPerimiter Parameters: int[] Returns: int Method signature: int getPerimiter(int[] a) (be sure your method is public)

### Constraints

-a will contain between 1 and 50 elements, inclusive.
-Each element of a will be between 1 and 50, inclusive.

### Examples

0)

 `{2,3,5,6,1}`
`Returns: 22`
 This column diagram is shown on the picture in the problem statement.
1)

 `{3,2,1}`
`Returns: 12`
2)

 `{2,2}`
`Returns: 8`
3)

 `{1,2,1}`
`Returns: 10`
4)

 `{1,2,3}`
`Returns: 12`

#### Problem url:

http://www.topcoder.com/stat?c=problem_statement&pm=10078

#### Problem stats url:

http://www.topcoder.com/tc?module=ProblemDetail&rd=13510&pm=10078

andrewzta

#### Testers:

PabloGilberto , Olexiy , marek.cygan , ivan_metelsky

#### Problem categories:

Simple Search, Iteration