#include <iostream>
#include <map>
#include <vector>
using namespace std;

using int64 = long long;

map<int, int64> counter;

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

    vector<int> a(N);
    for (int i = 0; i < N; i++) {
        cin >> a[i];
        counter[a[i]]++;
    }

    int64 ans = 0;
    for (int i = 0; i < N; i++) {
        ans += counter[X - a[i]];
    }
    cout << ans << endl;
    
    return 0;
}