#include <iostream>
#include<vector>
using namespace std;

int main() {
	vector<int> nums = {2,1,1,5,8};
    int k = 4;

    int low = 0;
    int sum = 0;
    int count = 0;
    int n = nums.size();

    for (int high = 0; high < n; high++) {

        sum += nums[high];

        while (sum >= k) {
            count += (n - high);
            sum -= nums[low];
            low++;
        }
    }

    cout << count;
	return 0;
}