#include <iostream>
#include<vector>
#include<unordered_map>
using namespace std;
 
int main() {
	// your code goes here
	vector<int> a={2,7,4,8,9,1,6};
	int k=9;
	int count=0;
	int sum=0;
	unordered_map<int,int> m;
	m[0]=1;
	for(int i=0;i<a.size();i++) {
		sum+=a[i];
		int ques=sum-k;
		if(m.find(ques)!=m.end()) {
			count+=m[ques];
		}
		m[sum]++;
	}
	cout<<count<<endl;
	return 0;
}