// ↘ ⬇ ⬇ ⬇ ⬇ ⬇ ↙
// ➡ @roadfromroi ⬅
// ↗ ⬆ ⬆ ⬆ ⬆ ⬆ ↖
#include <iostream>
#include "vector"
#include "algorithm"
#include "numeric"
#include "climits"
#include "iomanip"
#include "bitset"
#include "cmath"
#include "map"
#include "deque"
#include "array"
#include "set"
#define all(x) x.begin(), x.end()
using namespace std;
#define int long long
void upd(pair<int, int> &a, pair<int, int> b) {
if (a.first < b.first)
a = b;
if (a.first == b.first)
a = min(a, b);
}
struct myset {
set<pair<int, pair<int, int>>> st;
void add(int x, pair<int, int> y) {
while (1) {
auto it = st.lower_bound({x, {-1, -1}});
if (it == st.end())
break;
if (y >= ((*it).second))
st.erase(it);
else
break;
}
auto it = st.lower_bound({x+1, {-1, -1}});
if (it != st.begin()) {
it--;
if ((*it).second >= y)
return;
}
st.insert({x, y});
}
pair<int, int> get(int x) {
auto it = st.lower_bound({x+1, {-1, -1}});
if (it != st.begin()) {
it--;
return it->second;
}
return {-1e9, 0};
}
};
void solve() {
int n;
cin >> n;
vector<int> a(n);
vector<int> prf(n + 1);
for (int i = 0; i < n; ++i) {
cin >> a[i];
prf[i + 1] = prf[i] + a[i];
}
vector<pair<int, int>> dp(n + 1, {-1e9, 0});
dp[0] = {0, 0};
myset st;
st.add(0, {0, 0});
for (int i = 1; i <= n; ++i) {
//cout << i << endl;
int vl = prf[i];
pair<int, int> gt = st.get(vl);
upd(dp[i], {gt.first + 1, vl + gt.second});
st.add(dp[i].second + prf[i], {dp[i].first, -prf[i]});
}
cout << dp[n].first << '\n';
}
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int t = 1;
while (t--) {
solve();
}
}
