#include<bits/stdc++.h>
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);
using namespace std;
using ll = long long;

vector<ll> memo;
vector<ll> vec;
vector<ll> psum;

ll dp(ll target){
    if(memo[target] != -1) return memo[target];
    if(target == 0) return vec[0];
    ll l = 0, r = target -1;
    ll res = psum[target];
    while(l<=r){
        ll mid = l + (r - l) / 2;
        if(dp(mid) <= psum[target] - psum[mid]){
            res = psum[target] - psum[mid];
            l = mid +1;
        }
        else{
            r = mid - 1;
        }
    }
    return memo[target] = res;
}


int main(){
    fastio;
    ll n, inp, sum = 0;
    cin>>n;
    psum.resize(n+3);
    vec.resize(n+3, -1);
    memo.resize(n+3, -1);

    cin>>vec[0];
    psum[0] = vec[0];
    for(ll i = 1 ; i < n; i++){
        cin>>vec[i];
        psum[i] = psum[i-1] + vec[i];
        //cout << psum[i] << " ";
    }
    //cout << endl;
    ll ans = INT_MAX;
    for(ll i = 0; i < n; i++){
        // cout<< dp(i)<<endl;
        ans = min(ans,  max(dp(i), psum[n-1] - psum[i]));
    }
    cout<<ans<<endl;
}