#include<iostream>
#include<functional>
#include<queue>
#include<unordered_set>
using namespace std;
const int N=5e5+3;
typedef long long int ll;
ll a[N];
int n;

class cmp{
	public:
		bool operator()(const int i,const int j)const{
			return	a[i]>a[j];
		}
};

int deal(int id){
	if(id==n) return 0;
	else if(id<0) return n-1;
	else return id;
}

bool isvaild(ll d){
	for(int i=0;i<n;++i){
		ll num=d;
		int rmax=0;
		if(num>=a[i]){
			priority_queue<int,vector<int>,cmp> q;
			unordered_set<int> s;
			s.insert(i);
			rmax=max(rmax,i);
			//cout<<a[i]<<" ";
			//s.insert(deal(i+1));
			//s.insert(deal(i-1));
			s.insert(deal(i+1));
			s.insert(deal(i-1));
			//cout<<i<<" "<<deal(i+1)<<" "<<deal(i-1)<<" ";
			q.push(deal(i+1));
			q.push(deal(i-1));
			num+=a[i];
			bool flag=true;
			while(!q.empty()){
				if(num<a[q.top()]){
					flag=false;
					i=rmax; 
					break;
				}
				int cur=q.top();
				q.pop();
				rmax=max(cur,rmax);
				num+=a[cur];
				s.insert(cur);
				if(s.find(deal(cur+1))==s.end()){
					s.insert(deal(cur+1));
					q.push(deal(cur+1));
				}
				if(s.find(deal(cur-1))==s.end()){
					s.insert(deal(cur-1));
					q.push(deal(cur-1));
				}
			}
			//cout<<endl; 
			if(flag) return true;
		}
	}
	return false;
}

int main(){
	ll l=1e13+5,r=-1;
	cin>>n;
	for(int i=0;i<n;++i){
		cin>>a[i];
		l=min(l,a[i]);
		r=max(r,a[i]);
	}
	while(l<=r){
		ll mid=(r-l)/2+l;
		if(isvaild(mid)){
			r=mid-1;
		}else{
			l=mid+1;
		}
	}
	cout<<l;
	return 0;
}