#include <vector>
#include <algorithm>
#include <stdio.h>

#include <map>

using namespace std;

struct bet;

struct Ruleta{
	int* values;
	int size;
	int bets;
		
	Ruleta(int size){
		this->values = new int[size];
		this->size = size;
		this->bets = size / 2;
		
	}
	
	void set(int index,int value){
		values[index] = value;
	}
	
	int get(int index){
		int sum = 0;
		for(int i =index,j=0; j<bets;i++,j++){
			sum += values[i % size];
		}
		
		// printf("%d\n",sum);		
		//return new bet(index,value);	
		return sum;
	}

	~Ruleta(){
		delete[] values;
	}
};


struct bet {
	int start;
	int value;
	
	bet(int index, int value){
		this->start = index;
		this->value = value;
	}
};


int main(){


	int count = 0;
	scanf("%d",&count);
	
	while (count != 0){
	Ruleta* r = new Ruleta(count);
	
	int value= 0;
	for(int i =0;i<count;i++){
		scanf("%d", &value);
		r->set(i,value);
	}
	
	
	
	
	
	int cena=-1,tmp;
	// vector<int> v;
	map<int,int> bets;
	
	for(int i =0; i < count;i++){
		bets[i] = r->get(i);
	}
	
	//bool* occ = new bool[r->size];
	
	for(int i=0;i<count-2;i++){
		for(int j =i+1; j< min(i+r->bets+1, count-1); j++){
			for(int k = j+1; k< min(j+r->bets+1, count); k++){
				//for(int c=0;c<count;c++) occ[c] = false;
						
				/*for(int s =0; s<r->bets;s++){
					occ [(i+s)%r->size] = true;
					occ [(j+s)%r->size] = true;
					occ [(k+s)%r->size] = true;
				}*/
	
//				bool isOk = true;
				
	/*			for(int c=0;c<count;c++){
					if (!occ[c]) {isOk = false; break;}
				}
				
				if (isOk)					*/
				if (k <= count-r->bets -1+i) continue;
				
				tmp = bets[i]+bets[j]+bets[k];
				if (cena ==-1)	cena = tmp;
				else cena=(cena > tmp)?tmp : cena;


			}
		}
	}
	

	/*for(int i =0; i < count;i++){
		v.push_back(r->get(i));	
	}*/
	
//	sort(v.begin(),v.end());	
	
	/*int total = 0;
	for(int i =0; i<3;i++){
		total += v[i];		
	}*/
		
	printf("%d\n",cena);
	scanf("%d",&count);	
	delete r;
	}
	return 0;		

}