#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll t, n, m, k, l, r, op, x, y;
const ll inf = 0x3f3f3f3f3f3f3f3f;
bool flag ;
void solve() {
    y = m = -inf;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> k;
        if (k < 0)m = max(m, k);
        if (k > 0)flag = true;
        x = max(x + k, 0LL);
        y = max(y, x);
    }
    if (!flag)cout << m;
    else cout << y;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    solve();
    return 0;
}