viruses which are in capsules numbered from to , however not all capsules have a virus in them. has an extermination ray that can exterminate capsules in the range (This includes ones that contain a virus and ones that do not). However, he can only use the ray **up to** times.

Since capsules are quite expensive, can you tell

what is the minimum number of capsules that he has to destroy to exterminate the virus?#### Input Specification

First line, 3 integers , , , denoting the number of capsules, maximum number of times can use the ray, and the number of viruses, respectively.

Next lines, the capsule number , denoting where the virus resides in .

#### Output Specification

Output one integer, the minimum number of capsules that need to be destroyed in order to exterminate the virus.

#### Subtasks

For all subtasks:

##### Subtask 1 [30%]

##### Subtask 2 [70%]

No additional constraints.

#### Sample Input

```
10 2 5
3
4
5
7
10
```

#### Sample Output

`6`

#### Sample Explanation

and then on capsule , which will result in total capsules destroyed, including the capsules that did not have the virus in them.

can use the ray on capsules
## Comments