#include <bits/stdc++.h>
#define gibon ios::sync_with_stdio(false); cin.tie(0);
#define bp __builtin_popcount
#define fir first
#define sec second
#define pss pair<short, short>
#define pii pair<int, int>
#define pll pair<ll, ll>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
typedef long long ll;
using namespace std;
int dx[4]={0, 1, 0, -1}, dy[4]={1, 0, -1 , 0};
const int mxN=100005;
const int mxM=350;
const int mxK=350;
const ll MOD=998244353;
const ll INF=100000000000001;
int N;
ll A[mxN];
ll sum[mxN], cnt[mxN];
bool solv(ll num)
{
for(int i=0;i<N;i++) cnt[i]=sum[i]=0;
while(sum[0]<num)
{
sum[0]+=A[cnt[0]];
cnt[0]++;
}
for(int i=1;i<N;i++)
{
sum[i]=sum[i-1]-A[i-1];
cnt[i]=cnt[i-1]-1;
while(sum[i]<num)
{
sum[i]+=A[(i+cnt[i])%N];
cnt[i]++;
}
}
for(int i=0;i<N;i++)
{
int t1=i;
int t2=(t1+cnt[t1])%N;
int t3=(t2+cnt[t2])%N;
int tsum=cnt[t1]+cnt[t2]+cnt[t3];
if(tsum<=N) return true;
}
return false;
}
int main()
{
gibon
cin >> N;
for(int i=0;i<N;i++) cin >> A[i];
ll s=INF, e=0;
for(int i=0;i<N;i++) s=min(s, A[i]);
for(int i=0;i<N;i++) e+=A[i];
while(s!=e)
{
ll mid=(s+e)/2;
if(solv(mid)) s=mid+1;
else e=mid;
}
cout << s-1;
}
