#include <bits/stdc++.h>
using namespace std;

#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define RFOR(i,a,b) for(int i=(int)(b)-1;i>=(int)(a);i--)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define LL long long
#define INF INT_MAX/3

const double EPS = 1e-14;
const double PI  = acos(-1.0);


int main(){
  int n, x;

  cin >> n >> x;

  int a;
  vector<int> v(1e5+2);
  REP (i, 1e5 + 1) v[i] = 0;
  REP (i, n) {
    cin >> a;
    v[a]++;
  }

  LL ans = 0;
  FOR (i, 1, x + 1) {
    ans += v[i] * v[x - i];
  }

  cout << ans << endl;
}