#include <cstdio>
#define Nmax 6000002
using namespace std;

FILE *fi = fopen("ssm.in", "r");
FILE *fo = fopen("ssm.out", "w");

int n;
int v[Nmax];
int s[Nmax];
int max = 1<<31;

int main()
{
	fscanf(fi, "%d", &n);
	for (int i = 1; i<=n; i++)
	{
		fscanf(fi, "%d", &v[i]);
		s[i] = s[i-1] + v[i];
	}
	for (int i = n; i > 1; i--)
		for (int j = i-1; j>=1; j--)
			if (max < s[i] - s[j])
				max = s[i] - s[j];
	
	fprintf(fo, "%d\n", max);
	return 0;
}