#include <iostream>

using namespace std;
float a[1000010];
float a1[1000010];
int main() {
   int n;
   while(cin>>n)
   {
        for(int i=0;i<n;++i)
        {
            cin>>a[i];
        }
        float maxx = 0;
        a1[0] = a[0];
        for(int i = 0;i<n;++i)
        {
            a1[i] = max(a[i],a1[i-1]+a[i]);
            if(a1[i]>maxx)
            {
                maxx = a1[i];
            }
        }
        cout<<maxx<<endl;
   }
}
// 64 位输出请用 printf("%lld")