#include <bits/stdc++.h>

using namespace std;

int main()
{
    ifstream fin ("ssm.in");
    ofstream fout ("ssm.out");
    int n, maxSum = -(1 << 30), lastDp = 0, currentDp = 0;
    fin >> n;
    for (int i = 1; i <= n; ++i) {
        int x;
        fin >> x;
        currentDp = x;
        if (lastDp >= 0) {
            currentDp += lastDp;
        }
        maxSum = max (maxSum, currentDp);
        lastDp = currentDp;
    }
    fout << maxSum;
    return 0;
}