99分求调

#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<climits>
#include<iomanip>
#include<vector>
#include<queue>
#include<map>
#include<cctype>
#include<set>
using namespace std;
int n, d, a[1000005];
int bs(int l, int r) {
	int ans = 0;
	while(r < n) {
		if(a[r + 1] - a[l] <= d) {
			ans += r - l + 1;
			r ++;
		}else{
			l ++;
		}
	}
	return ans;
}
int main(){
	scanf("%d%d", &n, &d);
	for(int i = 1; i <= n; i ++) {
		scanf("%d", &a[i]);
	}
	sort(a + 1, a + n + 1);
	int ans = bs(1, 1);
	printf("%d\n", ans);
	return 0;
}