1 #include<stdio.h>
 2 #include<string.h>
 3 #include<math.h>
 4 #include<iostream>
 5 #include<algorithm>
 6 #include<queue>
 7 #include<vector>
 8 #include<set>
 9 #include<stack>
10 #include<string>
11 #include<sstream>
12 #include<map>
13 #include<cctype>
14 #include<limits.h>
15 using namespace std;
16 long long n,t,s,m1,m2,s1,s2;
17 int main()
18 {
19     while(scanf("%lld",&n)!=EOF)
20     {
21         scanf("%lld",&t);
22         s=m1=m2=s1=s2=t;
23         for(int i=1;i<n;i++)
24         {
25             scanf("%lld",&t);
26             s+=t;
27             if(s1>0)
28                 s1=s1+t;
29             else
30                 s1=t;
31             m1=max(m1,s1);
32             if(s2<0)
33                 s2+=t;
34             else
35                 s2=t;
36             m2=min(s2,m2);
37         }
38         printf("%lld\n",max(m1,s-m2));
39     }
40     return 0;
41 }