Since Max is wasting his time in his List I Communication credit lecture, he decided to start taking subsequences of arrays instead!

Specifically, he has integers, , and wants to take a subsequence of length , but to make his life even harder, his List I Communication credit professor adds a restriction: he must find the subsequence that has a length of with the minimum sum of the absolute difference between consecutive terms.

That is, he must minimize , where is the element of his subsequence and denotes the absolute difference between and .

Can you find the minimum sum of absolute differences for every possible subsequence of length ?

#### Constraints

##### Subtask 1 [40%]

##### Subtask 2 [60%]

No additional constraints.

#### Input Specification

The first line will contain two integers, and , the array's length and the subsequence's length, respectively.

The second line will contain integers, , the elements of the array.

#### Output Specification

Output the minimum sum of absolute differences between consecutive elements for any subsequence of length .

#### Sample Input 1

```
6 2
1 5 6 2 1 3
```

#### Sample Output 1

`0`

#### Explanation for Sample 1

It can be proven that the minimal sum is achieved with the subsequence .

#### Sample Input 2

```
6 4
3 2 6 2 7 9
```

#### Sample Output 2

`6`

#### Explanation for Sample 2

It can be proven that the minimal sum is achieved with the subsequence .

## Comments