#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=500013;
int a[N],b[N];
int n,dp[N];
int main(){
    int k=0;
    int n;
    cin>>n;
    for(int i=1;i<=n;i++)cin>>a[i],b[i]=b[i-1]+a[i];
    for(int i=1;i<=n;i++) {
        while(b[i]-b[k+1]>=dp[k+1]&&k+1<i)k++;
        dp[i]=b[i]-b[k];
    }
    int ans=2e9;
    for(int i=1;i<=n;i++)ans=min(ans,max(dp[i],b[n]-b[i]));
    cout<<ans<<'\n';
}