import sequtils,strutils,algorithm,math
import tables,intsets
proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "<stdio.h>" .}
proc scan(): int =
  while true:
    var k = getchar_unlocked()
    if k < '0' : break
    else: result = 10 * result + k.ord - '0'.ord
proc toCountSeq[T](x:seq[T]) : seq[tuple[k:T,v:int]] = toSeq(x.toCountTable().pairs)

let n = scan()
let x = scan()
var A = initTable[int,int]()
# var A = newSeq[int](n)

for _ in 0..<n:
  let a = scan()
  A[a] = A.mgetOrPut(a,0) + 1
let KV = toSeq(A.pairs).sorted(cmp)
let K = KV.mapIt(it[0])
let V = KV.mapIt(it[1])
var ans = 0
for ik,k in K:
  let i = K.lowerBound(x-k)
  if K[i] + k == x : ans += V[i]*V[ik]
echo ans