#include <bits/stdc++.h>
#define int long long
using namespace std;

ifstream fin("ssm.in");
ofstream fout("ssm.out");

int v[6000001];

signed main(){
    int n;
    fin >> n;
    for(int i = 1;i<=n;i++){
        fin >> v[i];
    }
    int sp=0;
    int ans=-1e9;
    int minim=0;
    for(int i = 1;i<=n;i++){
        sp+=v[i];
        ans=max(ans, sp-minim);
        minim=min(minim, sp);
    }
    fout<<ans;
}