内存限制：64 MiB 时间限制：5 Sec

A long, linear field has N (1 <= N <= 1,000) clumps of grass at
unique integer locations on what will be treated as a number line.
Think of the clumps as points on the number line.
Bessie starts at some specified integer location L on the number
line (1 <= L <= 1,000,000) and traverses the number line in the two
possible directions (sometimes reversing her direction) in order
to reach and eat all the clumps. She moves at a constant speed
(one unit of distance in one unit of time), and eats a clump instantly
when she encounters it.
Clumps that aren't eaten for a while get stale. We say the
``staleness'' of a clump is the amount of time that elapses from
when Bessie starts moving until she eats a clump. Bessie wants to
minimize the total staleness of all the clumps she eats.
Find the minimum total staleness that Bessie can achieve while
eating all the clumps.

* Line 1 : Two space-separated integers: N and L.
* Lines 2..N+1: Each line contains a single integer giving the
position P of a clump (1 <= P <= 1,000,000).

* Line 1: A single integer: the minimum total staleness Bessie can
achieve while eating all the clumps.

```
```

4 10

1

9

11

19

INPUT DETAILS:

Four clumps: at 1, 9, 11, and 19. Bessie starts at location 10.

```
```

44

OUTPUT DETAILS:

Bessie can follow this route:

* start at position 10 at time 0

* move to position 9, arriving at time 1

* move to position 11, arriving at time 3

* move to position 19, arriving at time 11

* move to position 1, arriving at time 29

giving her a total staleness of 1+3+11+29 = 44. There are other routes

with the same total staleness, but no route with a smaller one.