#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

#define pb push_back
#define fi first
#define se second
#define all(v) (v).begin(), (v).end()

const int MAXN = 5e5 + 5;
const ll INF = 1e18;

int ar[MAXN];
ll S[MAXN], M[MAXN], B[MAXN], c[MAXN];
int sz = 0;

bool bad(int l1, int l2, int l3) {
    return (B[l1]-B[l2])*(M[l3]-M[l1])>(B[l1]-B[l3])*(M[l2]-M[l1]);
}

void add(ll m, ll b) {
    M[sz] = m;
    B[sz] = b;
    sz++;
    while (sz >= 3 && bad(sz-3, sz-2, sz-1)) {
        swap(B[sz-1], B[sz-2]);
        swap(M[sz-1], M[sz-2]);
        sz--;
    }
}

inline ll eval(int pos, ll x) {
    return M[pos] * x + B[pos];
}

ll query(ll x) {
    int lo = 0, hi = sz-2, ans = 0;
    while (lo <= hi) {
        int mid = (lo + hi) >> 1;
        if (eval(mid, x) < eval(mid+1, x)) {
            ans = mid+1;
            lo = mid+1;
        } else
            hi = mid-1;
    }
    return eval(ans, x);
}

ll solve(int L, int R) {
    if (L >= R) return 0;
    int mid = (L + R) >> 1;
    ll ans = 0;
    sz = 0; // INITITTT
    vector<pair<ll, ll> > vec;
    ll sum = 0, val = 0;
    for (int i = mid; i >= L; i--) {
        val += ar[i] * 1LL * sum;
        sum += ar[i];
        vec.pb(make_pair(sum, val));
    }
    sort(all(vec));
    for (auto it : vec) {
        add(it.fi, it.se);
    }
    sum = val = 0;
    for (int i = mid + 1; i <= R; i++) {
        val += ar[i] * 1LL * sum;
        sum += ar[i];
        ans = max(ans, query(sum) + val);
    }
    return max(ans, max(solve(L, mid), solve(mid + 1, R)));
}

int main() {
    int n;
    scanf("%d", &n);
    for (int i = 1; i <= n; i++)
        scanf("%d", &ar[i]);
    /*
    ll ans = 0;
    for (int i = 1; i <= n; i++) {
        ll sum = 0, cur = 0;
        for (int j = i; j <= n; j++) {
            cur += sum * ar[j];
            ans = max(ans, cur);
            sum += ar[j];
        }
    }
    printf("%lld\n", ans);
    */
    printf("%lld\n", solve(1, n));
    return 0;
}