#include <bits/stdc++.h>
using namespace std;
#define REP(i,a) for(int i = 0; i < (a); i++)
#define ALL(a) (a).begin(),(a).end()
typedef long long ll;
typedef pair<int, int> P;
const int INF = 1e9;
const int MOD = 1e9 + 7;

signed main(){
    int n;
    ll x;
    cin >> n >> x;
    int a[n];
    REP(i,n){
        cin >> a[i];
    }
    sort(a, a + n);
    int ans = 0;
    REP(i,n){
        ans += upper_bound(a, a + n, x - a[i]) - lower_bound(a, a + n, x - a[i]);
    }
    cout << ans << endl;
}