open System

let solve a x =
  let countMap = 
    a |> Array.countBy id
    |> Map.ofArray
  let countMapSeq = countMap |> Map.toSeq

  countMapSeq |> Seq.map(fun (k, v) ->
    let k' = x - k
    countMap.TryFind k' |> function
    | None -> 0
    | Some c -> v * c)
  |> Seq.sum  

let R() = Console.ReadLine().Split() |> Array.map int

let N, X = 
  let t = R()
  t.[0], t.[1]

let a = R()

solve a X
|> Console.WriteLine