#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main() 
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int n,k;
	cin>>n>>k;
 
	long long sum=0;
	vector<int> hardness;
	for(int i=0;i<n;i++){
		int data;
		cin>>data;
		hardness.push_back(data);
	}
 
	sort(hardness.begin(),hardness.end());
	long long int i=0,j=n-1,ans=0;
	while(i<j){
		sum=hardness[i]+hardness[j];
		if(sum<k){
			ans+=(j-i);
			i++;
		}
		else j--;
	}
	cout<<ans;
	return 0;
}

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NyA0CjEwIDEgMyAxIDUgNSAw

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