#include<bits/stdc++.h>

using namespace std;

#define fRead(x)        freopen(x,"r",stdin)
#define fWrite(x)       freopen (x,"w",stdout)

#define LL              long long
#define ULL             unsigned long long
#define ff              first
#define ss              second
#define pb              push_back
#define PI              acos(-1.0)
#define mk              make_pair
#define pii             pair<int,int>
#define pll             pair<LL,LL>


#define min3(a,b,c)     min(a,min(b,c))
#define max3(a,b,c)     max(a,max(b,c))
#define min4(a,b,c,d)   min(a,min(b,min(c,d)))
#define max4(a,b,c,d)   max(a,max(b,max(c,d)))
#define SQR(a)          ((a)*(a))
#define FOR(i,a,b)      for(int i=a;i<=b;i++)
#define ROF(i,a,b)      for(int i=a;i>=b;i--)
#define REP(i,b)        for(int i=0;i<b;i++)
#define MEM(a,x)        memset(a,x,sizeof(a))
#define ABS(x)          ((x)<0?-(x):(x))

#define SORT(v)         sort(v.begin(),v.end())
#define REV(v)          reverse(v.begin(),v.end())
//#pragma GCC target ("avx2")
//#pragma GCC optimization ("O3")
//#pragma GCC optimization ("unroll-loops")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define FastRead        ios_base::sync_with_stdio(0);cin.tie(nullptr);
#ifdef VAMP
     #define debug(...) __f(#__VA_ARGS__, __VA_ARGS__)
    template < typename Arg1 >
    void __f(const char* name, Arg1&& arg1){
        cout << name << " = " << arg1 << std::endl;
    }
    template < typename Arg1, typename... Args>
    void __f(const char* names, Arg1&& arg1, Args&&... args){
        const char* comma = strchr(names+1, ',');
        cout.write(names, comma - names) << " = " << arg1 <<" | ";
        __f(comma+1, args...);
    }
#else
    #define debug(...)
#endif

const int N = 200005;
int n , ara[N];
LL sum[N];
pair<LL,LL>Left[N],Right[N];
LL getsum(int l,int r)
{
    return sum[r] - sum[l - 1];
}
LL partition(int l,int mid,int r)
{
    LL s1 = getsum(l,mid);
    LL s2 = getsum(mid + 1,r);
    return ABS(s1 - s2);
}

int32_t main()
{
    #ifdef VAMP
        clock_t tStart = clock();
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
    cin >> n;
    FOR(i,1,n)cin >> ara[i];
    FOR(i,1,n)sum[i] = sum[i - 1] + ara[i];

    int ptr = 1;
    for(int i = 2;i <= n - 2;i++){
        while(i - ptr > 1 and partition(1,ptr,i) >= partition(1,ptr + 1,i)){
            ptr++;
        }
        Left[i] = mk(getsum(1,ptr),getsum(ptr + 1,i));
    }
    ptr = n - 1;
    for(int i = n - 1;i >= 3;i--){
        while(ptr - i >= 1 and partition(i,ptr,n) >= partition(i,ptr - 1,n)){
            ptr--;
        }
        Right[i] = mk(getsum(i,ptr),getsum(ptr + 1,n));
    }
    LL ans = 1e18;
    for(int i = 2;i <= n - 2;i++){
        LL mx = max4(Left[i].ff,Left[i].ss,Right[i+1].ff,Right[i+1].ss);
        LL mn = min4(Left[i].ff,Left[i].ss,Right[i+1].ff,Right[i+1].ss);
        ans = min(ans,ABS(mx - mn));
    }
    cout << ans << "\n";
    #ifdef VAMP
        fprintf(stderr, "\n>> Runtime: %.10fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
    #endif
}


Measured memory_bytes: 8832