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

int pre[101010] = {0,};

int main() {
    int n;
    cin >> n;
    string s;
    cin >> s;
    
    for (int i = 1; i <= n; i++) {
        pre[i] = s[i] - '0' + pre[i-1];
    }
    
    long long cnt = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = i; j <= n; j++) {
            int sum = pre[j] - pre[i - 1]; 
            int len = j - i + 1;           

            if (sum == len) {
                cnt++;
            }
        }
    }
    cout << cnt;
    return 0;
}