#include <iostream>
using namespace std;

int main() {
	int n;
	cin >> n;
	
	int arr[n+1];
	
	for(int i=0; i<n; i++) {
		cin >> arr[i];
	}
	
	int k;
	cin >> k;
	
	int count = 0;
	
	int i=0; 
	int j = n-1;
	
	while(i < j) {
		if(arr[i] + arr[j] > k) {
			count += (j-i);
			j--;
		} else {
			i++;
		}
	}
	cout << " Count of Quadruplets: " << count;
	return 0;
}