#include <bits/stdc++.h>
using namespace std;
template <class T>
bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
  for (auto &v : vec) is >> v;
  return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
  for (int i = 0; i < vec.size(); i++) {
    os << vec[i];
    if (i + 1 != vec.size()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_set<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_multiset<T> &st) {
  for (auto itr = st.begin(); itr != st.end(); ++itr) {
    os << *itr;
    auto titr = itr;
    if (++titr != st.end()) os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << "(" << itr->first << ", " << itr->second << ")";
    auto titr = itr;
    if (++titr != mp.end()) os << " ";
  }
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp) {
  for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
    os << "(" << itr->first << ", " << itr->second << ")";
    auto titr = itr;
    if (++titr != mp.end()) os << " ";
  }
  return os;
}
using ll = long long int;
using P = pair<int, int>;
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
struct fast_io {
  fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(20);
  }
} fast_io_;
template <typename T>
struct ConvexHullTrick_ {
  vector<pair<T, T> > lines;
  function<bool(T l, T r)> comp;
  explicit ConvexHullTrick_(function<bool(T l, T r)> comp_ =
                                [](T l, T r) { return l >= r; })
      : comp(comp_) {}
  bool isnot_require(pair<T, T> l1, pair<T, T> l2, pair<T, T> l3) {
    if (l1 < l3) swap(l1, l3);
    return (l3.second - l2.second) * (l2.first - l1.first) >=
           (l2.second - l1.second) * (l3.first - l2.first);
  }
  void add(pair<T, T> p) {
    while (lines.size() >= 2 &&
           isnot_require(*(lines.end() - 2), *(lines.end() - 1), p))
      lines.pop_back();
    lines.push_back(p);
  }
  T f(int i, T x) { return lines[i].first * x + lines[i].second; }
  T val(T x) {
    int ld = -1;
    int rd = lines.size() - 1;
    while (rd - ld > 1) {
      int md = (rd + ld) / 2;
      if (comp(f(md, x), f(md + 1, x)))
        ld = md;
      else
        rd = md;
    }
    return f(rd, x);
  }
};
using ConvexHullTrickI = ConvexHullTrick_<int>;
using ConvexHullTrickL = ConvexHullTrick_<long long>;
int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  vector<ll> a(n);
  cin >> a;
  vector<ll> b(n), c(n);
  for (int i = (0); i < (n); ++i) {
    b[i] = i * a[i];
    c[i] = a[i];
    if (i > 0) {
      b[i] += b[i - 1];
      c[i] += c[i - 1];
    }
  }
  ConvexHullTrickL cht([](ll l, ll r) { return l >= r; });
  ll res = 0;
  chmax(res, a[0]);
  cht.add(make_pair(-1, 0));
  for (int r = (1); r < (n); ++r) {
    cht.add(make_pair(r - 1, b[r - 1] - (r - 1) * c[r - 1]));
    ll tmp = b[r] - cht.val(c[r]);
    chmax(res, tmp);
  }
  cout << res << endl;
  return 0;
}
