#pragma GCC optimize("O3","unroll-loops")
#pragma GCC target("sse4,tune=native")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef double ld;

const int INF = (int) 1e9 + 1e6;
const ll LINF = (ll) 1e18 + 1e9;
const ld EPS = (ld) 1e-10;
const ll MOD = (ll) 1e9 + 7;

#define sz(x) (int) (x).size()
#define mp(x, y) make_pair(x, y)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lb(s, t, x) (int) (lower_bound(s, t, x) - s)
#define ub(s, t, x) (int) (upper_bound(s, t, x) - s)
#define rep(i, f, t) for (auto i = f; i < t; ++(i))
#define per(i, f, t) for (auto i = (f); i >= (t); --(i))

ll power(ll x, ll y, ll mod = MOD) {
    if (y == 0) {
        return 1;
    }
    if (y & 1) {
        return power(x, y - 1, mod) * x % mod;
    } else {
        ll tmp = power(x, y / 2, mod);
        return tmp * tmp % mod;
    }
}

template<typename A, typename B> bool mini(A &x, const B &y) {
    if (y < x) {
        x = y;
        return true;
    }
    return false;
}

template<typename A, typename B> bool maxi(A &x, const B &y) {
    if (y > x) {
        x = y;
        return true;
    }
    return false;
}

void run();

#define TASK ""

int main() {
#ifdef LOCAL
    if (strlen(TASK) > 0) {
        cerr << "Reminder: you are using file i/o, filename: " TASK "!" << endl << endl;
    }
#endif
#ifndef LOCAL
    if (strlen(TASK)) {
        freopen(TASK ".in", "r", stdin);
        freopen(TASK ".out", "w", stdout);
    }
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
#endif
    cout << fixed << setprecision(12);
    run();
    return 0;
}

// == SOLUTION == //

struct Line {
    ll k, b;
    
    ll value(ll x) const {
        return k * x + b;
    }
    
    bool operator<(const Line &l) const {
        if (k != l.k) {
            return k < l.k;
        }
        return b > l.b;
    }
};

const int N = (int) 5e5 + 123;

int n;
int a[N];
ll ans = -LINF;

vector<Line> tmp;
vector<Line> lines;
vector<ll> points;

ll div_up(ll x, ll y) {
    if (y < 0) {
        x = -x;
        y = -y;
    }
    if (x < 0) {
        return x / y;
    } else {
        return (x + y - 1) / y;
    }
}

ll inter(Line a, Line b) {
    return div_up(b.b - a.b, a.k - b.k);
}

void add(Line l) {
    if (sz(lines) && lines.back().k == l.k) {
        return;
    }
    
    while (sz(points) && points.back() >= inter(l, lines.back())) {
        points.pop_back();
        lines.pop_back();
    }
    
    if (sz(lines)) {
        points.pb(inter(lines.back(), l));
    }
    lines.pb(l);
}

ll get(ll x) {
    int ind = (int) (upper_bound(all(points), x) - points.begin());
    return lines[ind].value(x);
}

void build() {
    lines.clear();
    points.clear();
    sort(all(tmp));
    for (auto &l : tmp) add(l);
    tmp.clear();
}

void solve(int l, int r) {
    if (l >= r) return;
    if (r - l <= 5) {
        rep(i, l, r) {
            ll res = 0;
            ll sum = 0;
            rep(j, i, r) {
                res += a[j] * sum;
                sum += a[j];
                maxi(ans, res);
            }
        }
        return;
    }
    
    int mid = (l + r) / 2;
    solve(l, mid);
    solve(mid, r);
    
    ll res = 0;
    ll sum = 0;
    
    per(i, mid - 1, l) {
        res += a[i] * sum;
        sum += a[i];
        tmp.pb({sum, res});
    }
    
    build();
    
    res = 0;
    sum = 0;
    rep(i, mid, r) {
        res += a[i] * sum;
        sum += a[i];
        ll cur = res + get(sum);
        maxi(ans, cur);
    }
}

void run() {
    cin >> n;
    rep(i, 0, n) {
        cin >> a[i];
    }
    solve(0, n);
    cout << ans << "\n";
}