#include <bits/stdc++.h>
using namespace std;
const int MAX = 510000;
const int MOD = 1000000007;
long long fac[MAX], finv[MAX], inv[MAX];
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
long long COM(int n, int k) {
  if (n < k) return 0;
  if (n < 0 || k < 0) return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
int main() {
  int N;
  cin >> N;
  vector<long long> A(N);
  long long s = 0;
  map<long long, long long> mp;
  mp[0] = 1;
  for (int i = 0; i < (N); ++i) {
    cin >> A[i];
    s += A[i];
    mp[s]++;
  }
  COMinit();
  long long ans = 0;
  for (auto itr = mp.begin(); itr != mp.end(); itr++) {
    if (itr->second > 1) {
      ans += COM(itr->second, 2);
    }
  }
  cout << ans << endl;
  return 0;
}
