*山

#include<bits/stdc++.h>
using namespace std;
int main(){int n,a=-10000000,cnt=0, ma=0;
cin>>n;for(int i=0;i<n;i++){int t;cin>>t;
cnt+=t;int s=cnt-(cnt*2);if(cnt+ma>a){
a=cnt+ma;}if(s>ma){ma=s;}}cout<<a;}