Grazing on the Run

A long linear field has N (1 <= N <= 1,000) clumps of grass at
unique 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 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.

PROBLEM NAME: ontherun

INPUT FORMAT:

* 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).

SAMPLE INPUT:

4 10
1
9
11
19

INPUT DETAILS:

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

OUTPUT FORMAT:

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

SAMPLE OUTPUT:

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.