#include <iostream>
using namespace std;

int main() {
	int n;
    cin>>n;
    int k;
    cin>>k;
    int arr[n];
    for(int i=0;i<n;i++){
        cin>>arr[i];
    }
    int ans=0;
	int start=0, end=n-1;
	while(start < end){
		int sum = arr[start] + arr[end];
		if(sum <= k)
			start++;
		else{
			ans=ans+end-start;
			end--;
		}
	}
	cout<<ans;
	return 0;
}