#include <bits/stdc++.h>
using namespace std;
const int inf = 0x3f3f3f3f;
long long nums[200009];
long long m;
int main() {
  int n;
  int ans = 0;
  while (~scanf("%d", &n)) {
    for (int i = 0; i < n; i++) {
      scanf("%lld", &m);
      for (int j = i; j >= 0; j--) {
        nums[j] += m;
        if (nums[j] == 0) {
          ans++;
        }
      }
    }
    printf("%d\n", ans);
  }
  return 0;
}
