#include <bits/stdc++.h>

using namespace std;

long largestValue(vector <int> a) {
   long s=0;
  
    int max_ending_here=0;
    int max_so_far=0;
    int start =0;
    int end=0;


    for(int i=0;i< a.size();i++){
        max_ending_here=max_ending_here+a[i];
        if(max_ending_here<0)
        {
            start=i+1; //Every time it goes negative start from next index
            max_ending_here=0;
        }
        else 
            end =i; //As long as its positive keep updating the end

        if(max_so_far<max_ending_here){
            max_so_far=max_ending_here;
        }

    }
    for(int i=start;i<end-1;i++)
        for(int j=i+1;j<=end;j++)
         s=s+a[i]+a[j];
return s;
}

int main() {
    int n;
    cin >> n;
    vector<int> A(n);
    for(int A_i = 0; A_i < n; A_i++){
       cin >> A[A_i];
    }
    long result = largestValue(A);
    cout << result << endl;
    return 0;
}