#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 5;
int n, c, a[MAXN], fnd, ans;
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> c;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    sort(a + 1, a + 1 + n);
    for (int i = 1; i <= n; i++)
        for (fnd = lower_bound(a + 1, a + 1 + n, a[i] - c) - a; fnd <= n && fnd != i && a[fnd] == a[i] - c; ans++, fnd++);
    cout << ans;
    return 0;
}