#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 5e5 + 55;
//
//
int a[N], p[N];
ll sum(int l, int r) {
return p[r] - p[l - 1];
}
using pll = pair<ll,ll>;
map<ll,pll> mp;
const ll INF = 1e17;
const ll HALF = INF / 2;
void upd(ll a, pll b) {
a += HALF;
while (a < INF) {
mp[a] = max(mp[a], b);
a |= a + 1;
}
}
pll get(ll a) {
a += HALF;
pll b = {-1, -1};
while (a >= 0) {
if (mp.count(a)) b = max(b, mp[a]);
a &= a + 1;
a--;
}
return b;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
int n;
cin >> n;
for (int i = 1 ; i <= n ; ++ i) {
cin >> a[i];
p[i] = a[i] + p[i - 1];
}
ll mx = 1;
//upd(-sum(1, n), {0, 0});
//for (int i = 1 ; i <= n ; ++ i) {
//auto [s, j] = get(-sum(i + 1, n));
//j++;
//mx = max(mx, s + 1);
//upd(sum(j, i) - sum(i + 1, n), {s + 1, i});
//cout << i << " " << s << " " << j << " " << sum(j, i) - sum(i + 1, n) << "\n";
//}
upd(0, {0, 0});
for (int i = 1 ; i <= n ; ++ i) {
auto [s, j] = get(p[i]);
j++;
mx = max(mx, s + 1);
upd(p[i] * 2 - p[j - 1], {s + 1, i});
//cout << i << " " << s << " " << j << " " << sum(j, i) - sum(i + 1, n) << "\n";
}
cout << mx;
}
