#include<iostream>

#include<cstdio>

#include<cstdlib>

#include<algorithm>

#include<cmath>

#include<cstring>

#define ll long long

using namespace std;

const int N=200005;

inline int read(){

	int x=0; char ch=getchar();

	for(;!isdigit(ch);ch=getchar());

	for(;isdigit(ch);ch=getchar()) x=x*10+ch-'0';

	return x;

}

int n,px,py;

ll a[N],ans=1e18,tot,now,mx,mn;

inline void update(){

	if(now<mn) mn=now;

	else if(now>mx) mx=now;

}

inline void solve(){

	for(int i=1;i<=n;i++){

		while(px<i&&a[px+1]*2ll<=a[i]) px++;

		while(py<n&&a[py+1]*2ll<=tot+a[i]) py++;

		for(int u=px+1;u>=px;u--)

		    for(int v=py+1;v>=py;v--){

		        mx=mn=a[u];

		    	now=a[i]-a[u],update();

		    	now=a[v]-a[i],update();

		    	now=tot-a[v],update();

		    	ans=min(ans,mx-mn);

			}

	}

}

int main(){

	n=read();

	for(int i=1;i<=n;i++) a[i]=a[i-1]+(ll)read();

	a[n+1]=a[n+2]=tot=a[n];

	solve(),printf("%lld\n",ans);

	return 0;

}