Roy is helping the police department of his city in crime fighting. Today, they informed him about a new planned operation. The city has only one road and criminals live there! To catch these criminals, the police department has to recruit some police officers and give each of them $ as wages. A police officer can start his operation from any point , drive his car to point in a straight line, and catch all the criminals who live on this way.

The cost of the fuel used =

Thus, find the minimum amount of money spent to catch all the criminals.

#### Input Format

1st line: Number of criminals () and value of

2nd line: Position of where the criminals live

#### Output Format

1st line: Minimum amount of money spent.

#### Constraints

Subtask 1 (20%): . .

Subtask 2 (20%): . .

Subtask 3 (60%): . .

Subtask 4 (0%): Sample Testcases.

#### Sample

###### Input

```
5 10
1 4 5 6 9
```

###### Output

`34`

###### Explanation

One police deployed at position 1 = $10One police deployed at position 4, travel until position 6 = $10 + $(2 × 2) = $14

One police deployed at position 9 = $10

Total = $34

Original Problem Author: Bidhan; Problem Resource: HackerRank

## Comments

206116

Yes and yes.