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

int main() {
    int n;
    cin >> n;
    long c;
    cin >> c;
    multiset<long> s;
    while (n--) {
        int num;
        cin >> num;
        s.insert(num);
    }

    int count = 0;
    for (auto it = s.begin(); it != s.end(); ++it) {
        count += s.count(*it + c);
    }
    cout << count << endl;
}