#include <iostream>
#include <fstream>
///T5
using namespace std;
ifstream fin("ssm.in");
ofstream fout("ssm.out");

long long x, s, smax, n;
int main()
{
    fin >>n; fin >> x;
    s = smax = x;
    for(int i = 2; i <= n; i++){
        fin >> x;
        if(x>0){
            if(s<0) s = x;
                else s+=x;

            if(s > smax)
                    smax = s;
        } else
            s += x;
    }

    fout << smax;

    fin.close(); fout.close();
    return 0;
}