#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
using namespace std;
int n,tmp1,tmp2,maxn,head,tail,o,i,tmp;
int queue[200000];
int f[200000];
int a[200000];
int s[200000];
int main()
{
	freopen("circlea.in","r",stdin);
	freopen("circlea.out","w",stdout);
	scanf("%d",&n);
	s[0]=0;
	for (i=1;i<=n;i++){
		scanf("%d",&a[i]);
		s[i]=s[i-1]+a[i];
	}
	o=s[n]/2;
	if (s[n]%2!=0) o++;
	memset(queue,0,sizeof(queue));
	head=1;
	tail=1;
	queue[tail]=a[1];
	maxn=0;
	while (tail<=n){
		tail++;
		queue[tail]=queue[tail-1]+a[tail];
		tmp1=queue[tail];
		tmp2=s[n]-queue[tail];
		tmp=tmp1<tmp2?tmp1:tmp2;
		if (tmp>maxn) maxn=tmp;
		while (queue[tail]>s[n]-queue[tail]){
			queue[tail]-=a[head++];
			tmp1=queue[tail];
			tmp2=s[n]-queue[tail];
			tmp=tmp1<tmp2?tmp1:tmp2;
			if (tmp>maxn) maxn=tmp;
		}
	}
	printf("%d",maxn);
	return 0;
}