open System
open System.Collections.Generic
open System.Linq
open System

// Following contents are my library. The Main processes are on the bottom of this code.

let puts = Console.WriteLine : 'a -> unit
let put = Console.Write : 'a -> unit
let Read() = Console.ReadLine()
let Reads () = Console.ReadLine().Split()
let ReadInt () = Read() |> int
let ReadDouble () = Reads() |> (fun x -> x.[0], x.[1])
let ReadTriple () = Reads() |> (fun x -> x.[0], x.[1], x.[2])
let ReadQuadruple () = Reads() |> (fun x -> x.[0], x.[1], x.[2], x.[3])
let FuncDouble f1 f2 (t1, t2) = (f1 t1, f2 t2)
let FuncTriple f1 f2 f3 (t1, t2, t3) = (f1 t1, f2 t2, f3 t3)
let FuncQuadruple f1 f2 f3 f4 (t1, t2, t3, t4) = (f1 t1, f2 t2, f3 t3, f4 t4)

let ReadIntQuadruple () = ReadQuadruple() |> FuncQuadruple int int int int
let ReadIntTriple () = ReadTriple () |> FuncTriple int int int
let ReadIntDouble () = ReadDouble () |> FuncDouble int int
let ensmallen l = l % 1000000007L
let manhattan x y = abs (fst x - fst y) + abs (snd x - snd y)
let sayYESNO b = if b then puts "YES" else puts "NO"


// The main contents of this submission are below this line.

let n, k = (ReadInt(), ReadInt())
Reads() |> Seq.map int
    |> Seq.sumBy (fun i -> min i (k - i))
    |> ((*)2)
    |> puts
