#include <iostream>
#include <algorithm>

using namespace std;
using LL = long long;
using ULL = unsigned long long;

int main() {
    int N, X;
    cin >> N >> X;

    int a[N];
    for (int i = 0; i < N; i++) cin >> a[i];
    sort(a, a + N);

    LL ans = 0;
    for (int i = 0; i < N; i++) {
        int *p = lower_bound(a, a + N, X - a[i]);
        int *q = upper_bound(a, a + N, X - a[i]);
        for (int j = p - a; j < q - a; j++) {
            if (a[i] + a[j] == X) ans++;
        }
    }

    cout << ans << endl;
}