#define _USE_MATH_DEFINES
 
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <vector>
#include <math.h>

using namespace std;

int main(){
	int n;

	while(cin >> n){
		int max = 0;
		int soremade = 0;
		int mae = 0;
		int ima = 0;

		if(n==0) break;
		
		cin >> mae;
		max = mae;

		for(int i=1;i<n;i++){
			if(mae > soremade+mae){
				soremade = mae;
			}else{
				soremade += mae;
			}
			
			cin >> ima;
			
			if(max < ima+soremade){
				max = ima+soremade;
			}
			mae = ima;
		}

		cout << max << endl;
	}

	return 0;
}