#include<cstdlib>
#include<cassert>
#include<cstdio>
#include<vector>
#include<queue>
#include<map>
#include<cctype>
#include<string>
#include<cstring>
#include<algorithm>
#include<unordered_set>
#include<unordered_map>
using namespace std;

#define fisier 0
#define consola 0

#if fisier
 #include<fstream>
 ifstream cin("fisier.in");
 ofstream cout("fisier.out");
#else
 #include<iostream> 
#endif

const int MAX_N = 1003;
long long n,i,d[MAX_N],sol[MAX_N];
long long x[MAX_N],maxim,c1,c2,j;
long long mmx=-2345;
bool pozitive;

int main(){
    cin>>n; 
    
    if(n==1){
    	     cin>>x[1];
    	     cout<<x[1];
	        }
    else{
    pozitive=0;
    for(j=1;j<=n;j++)
       {
       	cin>>x[1]; if(x[1]>=0) pozitive=1;
       	           if(x[1]>mmx) mmx=x[1];
       	           
        d[1]=c1=c2=maxim=max(max(c1+x[1],0LL),max(x[1],x[1]+sol[1]));; 
     
        for(i=2;i<=n;i++)
          {
           cin>>x[i]; if(x[i]>=0) pozitive=1;
                      if(x[i]>mmx) mmx=x[i];
           
           if(c1+x[i]>=x[i]) c2=c1+x[i];
           else c2=x[i]; 
           
           c2=max(max(c1+x[i],0LL),max(x[i],x[i]+sol[i]));
           
           if(c2>maxim) maxim=c2;
         
           c1=c2;
           d[i]=c2;
          }
          
        for(i=1;i<=n;i++)
          sol[i]=d[i];
        /*  
        for(i=1;i<=n;i++)
	      cout<<sol[i]<<" "; 
	    cout<<endl;
	    */
	   }
   
    
    if(pozitive) cout<<maxim;
    else cout<<mmx;
    }
    #if fisier
     cin.close();
     cout.close();
    #endif
    
    #if consola
     system("pause");
    #endif
    return 0;
}