/*
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") ./**/

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <ctime>
#include <vector>
#include <queue>
#include <bitset>
#include <cmath>
#include <time.h>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <stdlib.h>
#include <deque>
#include <iomanip>
#include <complex>
//#include <ext/rope>

using namespace std;
//using namespace __gnu_cxx;

//defines
typedef long long ll;
typedef long double ld;
#define TIME clock() * 1.0 / CLOCKS_PER_SEC
#define fast_read cin.sync_with_stdio(0)
#define PREX(number) cout << fixed << setprecision(number)
#define nul point(0, 0)
#define random srand(time(NULL))
#define rand_int abs((rand() << 15) | rand())
#define str_to_int(stroka) atoi(stroka.c_str())
#define str_to_ll(stroka) atoll(stroka.c_str())
#define str_to_double(stroka) atof(stroka.c_str())
#define what_is(x) cerr << #x << " is " << x << endl
#define solve_system int number; cin >> number; for (int i = 0; i < number; i++) solve()
#define solve_system_scanf int number; scanf("%d", &number); forn(i, 0, number) solve()

//easy functions
template< typename T >
T gcd(T a, T b) { return a ? gcd(b % a, a) : b; }
template< typename T >
T lcm(T a, T b) { return (a / gcd(a, b)) * b; }
bool is_down(char x) { return ('a' <= x && x <= 'z'); }
bool is_upper(char x) { return ('A' <= x && x <= 'Z'); }
bool is_digit(char x) { return ('0' <= x && x <= '9'); }

//constants
const ld pi = 3.141592653589793238462643383279;
const ld log23 = 1.58496250072115618145373894394781;
const ld eps = 1e-8;
const ld zero = 0;
const ll INF = 1e18;
const int COUT = 30;
const int prost = 239;
const ll prost64 = 239;
const int two = 2;
const int thr = 3;
const ll sr = 31;
const ll MOD = 1e9 + 7;
const int BIG = 2 * 1e9 + 1;
const int alf = 26;
const int MAX_N = 5 * 1e5 + 1;
const int MAX_M = 2001;
const int MAX_T = (1 << 20);
const int B = trunc(sqrt(MAX_N)) + 1;
const int MAX_LOG = 19;
const int km = (1 << 18);
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, 1, 0, -1};
const int dxo[8] = {-1, -1, -1, 0, 1, 1, 1, 0};
const int dyo[8] = {-1, 0, 1, 1, 1, 0, -1, -1};
const int bit_max = 32;
const int dig = 10;
const string str_alf = "abcdefghijklmnopqrstuvwxyz";
const string str_alf_big = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const int day[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int digarr[10] = {6, 2, 5, 5, 4, 5, 6, 3, 7, 6};
const int bt = 31;

// Code starts here

struct point
{
    ld x, y;

    point()
    {
        x = y = 0;
    }

    point(ld a, ld b)
    {
        x = a;
        y = b;
    }

    bool operator<(const point &p) const
    {
        return x < p.x;
    }
};

struct line
{
    ll a, b;

    line()
    {
        a = b = 0;
    }

    line(ll x, ll y)
    {
        a = x;
        b = y;
    }

    ll gett(ll x)
    {
        return (a + b * x);
    }

    bool operator<(const line &l) const
    {
        return b < l.b;
    }
};

point inter(line a, line b)
{
    ld x = (ld)(b.a - a.a) / (ld)(a.b - b.b);
    ld y = 0;
    return point(x, y);
}

vector<pair<point, line> > q;

void add(ll a, ll b)
{
    line l = line(a, b);
    while (!q.empty())
    {
        point r = q.back().first;
        line u = q.back().second;
        point e = inter(u, l);
        if (e.x <= r.x)
        {
            q.pop_back();
            continue;
        }
        q.push_back(make_pair(e, l));
        break;
    }
    if (q.empty())
        q.push_back(make_pair(point(-BIG, 0), l));
}

ll gett(ll x)
{
    int ind = upper_bound(q.begin(), q.end(), make_pair(point(x, 0), line(0, 0))) - q.begin();
    ind--;
    return q[ind].second.gett(x);
}

int n;
ll a[MAX_N];

ll func(int l, int r)
{
    if (r - l == 1)
        return 0;
    int mid = (l + r) >> 1;
    ll ans = max(func(l, mid), func(mid, r));
    vector<pair<ll, ll> > ln;
    q.clear();
    ll sm = 0;
    ll sq = 0;
    for (int i = mid; i < r; i++)
    {
        sm += a[i];
        sq += a[i] * a[i];
        ln.push_back(make_pair(2 * sm, sm * sm - sq));
    }
    sort(ln.begin(), ln.end());
    int it = 0;
    for (pair<ll, ll> t : ln)
    {
        if (it == (int)ln.size() - 1 || ln[it + 1].first > ln[it].first)
            add(t.second, t.first);
        it++;
    }
    sm = 0;
    sq = 0;
    for (int i = mid - 1; i >= l; i--)
    {
        sm += a[i];
        sq += a[i] * a[i];
        ans = max(ans, gett(sm) + (sm * sm - sq));
    }
    return ans;
}

int main()
{   /*
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif /**/
    fast_read;
    cin >> n;
    for (int i = 0; i < n; i++)
        cin >> a[i];
    cout << func(0, n) / 2LL;
    return 0;
}