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

int main() {
	vector<int> nums={2,6,4,3,6,8,9};
	int low=0;
	int high=0;
	int count=0;
	int k=3;
	multiset<int> s;
	
	for(int high=0;high<nums.size();high++) {
		s.insert(nums[high]);
		while(*s.rbegin()-*s.begin()>k) {
			s.erase(s.find(nums[low]));
			low++;
		} 
		count+=high-low+1;
	}
	cout<<count<<endl;
	return 0;
}