#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<cstring>
using namespace std;
int n,a[20010],s,sum=0,r;
int main(){
	freopen("costume.in","r",stdin);
	freopen("costume.out","w",stdout);
    scanf("%d%d",&n,&s);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);
    sort(a+1,a+1+n);
    r=n;
    for(int i=1;;i++){
    	while(a[i]+a[r]>s&&r>i)r--;
    	if(r==i)break;
    	sum+=r-i;
    }
    printf("%d",sum);
    return 0;
}