#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 5;
int n;
int a[N];
int main() {
cin >> n;
long long mn = 0, s = 0, ans = 0; // mn = s0 = 0;
for (int i = 1; i <= n; i ++){
cin >> a[i];
s += a[i];
ans = max(ans, s - mn);
mn = min(mn, s);
}
cout << ans;
return 0;
}
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