#include<bits/stdc++.h>
using namespace std;
int n,a[114514],ans=INT_MIN;
int s[114514];
deque<int> q;
int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++)
	  cin>>a[i];
	q.push_back(0),s[0]=0;
	for(int i=1;i<=n;i++)
	{
		s[i]=a[i]+s[i-1];
		ans=max(ans,s[i]-s[q.front()]);
		while(!q.empty()&&s[i]<=s[q.back()])
		  q.pop_back();
		q.push_back(i);
	}
	printf("%d\n",ans);
	return 0;
}