D.cpp

/*
 © 2020-09-28 03:05:02 Franco1010 All Rights Reserved
*/

#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define f first
#define s second
#define fore(i,a,b) for(int i = (a), ThxMK = (b); i < ThxMK; ++i)
#define pb push_back
#define all(s) begin(s), end(s)
#define _ ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define sz(s) int(s.size())
#define ENDL '\n'
using namespace std;
typedef long double ld;
typedef long long lli;
typedef pair<lli,lli> ii;
typedef vector<lli> vi;
#define deb(x) cout << #x": " << (x) << endl;

int main(){ _
  lli n ;cin >> n;
  lli sum = 0;
  lli res = 0;
  set<lli> st = {0};
  fore(i, 0, n){
    lli x; cin >> x;
    sum += x;
    if(st.count(sum)){
      res++;
      st = {0, x};
      sum = x;
    }else st.insert(sum);
  }
  cout << res << ENDL;
  return 0;
}