#include <bits/stdc++.h>
using namespace std;
/*{{{*/  //template
#define rep(i,n) for(int i=0;i<(int)(n);i++)
constexpr int INF = numeric_limits<int>::max()/2;
constexpr long long LINF = numeric_limits<long long>::max()/3;
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define sz(x) (int)(x).size()
#define debug(x) cerr<<#x<<":"<<x<<endl
#define debug2(x,y) cerr<<#x<<","<<#y":"<<x<<","<<y<<endl
//struct fin{ fin(){ cin.tie(0); ios::sync_with_stdio(false); } } fin_;
struct Double{ double d; explicit Double(double x) : d(x){} };
ostream& operator<<(ostream& os,const Double x){ os << fixed << setprecision(20) << x.d; return os; }
template<typename T> ostream& operator<<(ostream& os,const vector<T>& vec){ os << "["; for(const auto& v : vec){ os << v << ","; } os << "]"; return os; }
template<typename T,typename U> ostream& operator<<(ostream& os,const pair<T,U>& p){ os << "(" << p.first << ","<< p.second <<")"; return os; }
template<typename T> ostream& operator<<(ostream& os,const set<T>& st){ os<<"{"; for(T v:st) os<<v<<","; os <<"}"; return os; }
template<typename T,typename U> inline void chmax(T &x,U y){ if(y>x) x = y; }
template<typename T,typename U> inline void chmin(T &x,U y){ if(y<x) x = y; }
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
ll gcd(ll a,ll b){ if(b==0) return a; else return gcd(b,a%b); }
//constexpr double eps = 1e-14; 
constexpr double eps = 1e-10; 
constexpr ll mod = 1e9+7;
const int dx[]={1,0,-1,0} ,dy[] = {0,1,0,-1};
/*}}}*/

struct RSQ{
    public:
        int n;
        vector<ll> data;
        RSQ(int n_){
            n = 1;
            while(n<n_) n*=2;
            data.resize(2*n-1);
            for(int i=0;i<2*n-1;i++) data[i]=0;
        }
        void update(int k,ll a){
            k+=n-1;
            data[k]=a;
            while(k>0){
                k=(k-1)/2;
                data[k]=data[k*2+1]+data[k*2+2];
            }
        }
        ll query(int a,int b,int k,int l,int r){
            if(r<=a or b<=l) return 0;
            if(a<=l and r<=b) return data[k];
            else return query(a,b,k*2+1,l,(l+r)/2)+query(a,b,k*2+2,(l+r)/2,r);
        }
        ll query(int a,int b){ return query(a,b,0,0,n); }
};

int N;
ll A[200005];

int main(){
    cin >> N;
    rep(i,N) cin >> A[i];

    RSQ seg(N);
    rep(i,N) seg.update(i,A[i]);

    ll ans = LINF;

    for(int i=0;i<N;i++){
        // B,C = [0,i)
        ll sum = seg.query(0,i);

        // B = [0,t) , C = [t,i)
        int l,r;
        l = 0;
        r = i;
        while(r-l>1){
            int m = (l+r)/2;
            ll sb = seg.query(0,m);

            if(sb < sum/2){
                l = m;
            }else{
                r = m;
            }
        }

        int l1 = l;

        // D,E = [i,N)
        sum = seg.query(i,N);
        l = i;
        r = N;
        while(r-l>1){
            int m = (l+r)/2;
            ll sd = seg.query(i,m);

            if(sd < sum/2){
                l = m;
            }else{
                r = m;
            }
        }

        int l2 = l;


        for(int d1=0;d1<=1;d1++) for(int d2=0;d2<=1;d2++){
            int p = l1 + d1;
            int q = l2 + d2;

            ll b = seg.query(0,p);
            ll c = seg.query(0,i) - b;
            ll d = seg.query(i,q);
            ll e = seg.query(i,N) - d;

            ll mn=min({b,c,d,e});
            ll mx=max({b,c,d,e});

            ans = min(ans,mx-mn);
        }
    }
    cout << ans << endl;
}


Measured memory_bytes: 5888