#include <bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i, n) for (long long i = 0, max_i = (n); i < max_i; i++)
#define REPI(i, a, b) for (long long i = (a), max_i = (b); i < max_i; i++)
#define ALL(obj) begin(obj), end(obj)
#define RALL(obj) rbegin(obj), rend(obj)
#define fi first
#define se second
using ii = pair<int, int>;
template <class T> inline bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template <class T> inline bool chmin(T &a, const T &b) { if (a > b) { a = b; return true; } return false; }

// debug
template <class T> ostream& operator<<(ostream &s, vector<T>& d) { REP (i, d.size()) s << d[i] << (i == d.size() - 1 ? "" : " "); return s; }
template <class T> ostream& operator<<(ostream &s, vector<vector<T>>& d) { REP (i, d.size()) s << d[i] << (i == d.size() - 1 ? "" : "\n"); return s; }
template <class T, class S> ostream& operator<<(ostream &s, pair<T, S>& p) { s << "{" << p.first << ", " << p.second << "}"; return s; }
template <class T, class S> ostream& operator<<(ostream& s, map<T, S> m) { for (auto it = m.begin(); it != m.end(); it++) { s << *it << (next(it) == m.end() ? "" : "\n"); } return s; }
#ifdef _MY_DEBUG
  #define dump(...) cerr << "/* " << #__VA_ARGS__ << " :[" << __LINE__ << ":" << __FUNCTION__ << "]" << endl, dump_func(__VA_ARGS__), cerr << "*/\n\n";
#else
  #define dump(...)
#endif
void dump_func() { cerr << endl; }
template <class Head, class... Tail> void dump_func(Head&& h, Tail&&... t) { cerr << h << (sizeof...(Tail) == 0 ? "" : ", "), dump_func(forward<Tail>(t)...); }

struct Fast { Fast() { cin.tie(0); ios::sync_with_stdio(false); } } fast;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
constexpr int MOD = 1000000007;

// 0-indexed
class BinaryIndexedTree {
  int max_pow; // N以下の最大の2べき
  void init() {
    for (max_pow = 1; max_pow <= N / 2; max_pow *= 2);
    REP (i, N - 1) if ((i | (i + 1)) < N) {
      bit[i | (i + 1)] += bit[i];
    }
  }
public:
  vector<int> bit; int N;
  BinaryIndexedTree(int n, int x = 0) : N(n), bit(n, x) { init(); }
  BinaryIndexedTree(const vector<int>& a) : N(a.size()), bit(a) { init(); }
  // k番目にxを加算
  void add(int k, int x) {
    for (int i = k; i < N; i |= i + 1) { bit[i] += x; }
  }

  // [0, k)、k == 0のときは0を返す
  int sum(int k) {
    int ret = 0;
    for (int i = k - 1; i >= 0; i = (i & (i + 1)) - 1) {
      ret += bit[i];
    }
    return ret;
  }
  int sum() { return sum(N); }

  // [a, b)
  int query(int a, int b) {
    assert(a <= b);
    return sum(b) - sum(a);
  }
  int operator[](int k) {
    return query(k, k + 1);
  }

  // k番目をxに
  void update(int k, int x) {
    add(k, x - operator[](k));
  }

  // 注: 中身が全て正のときしか動かない
  // sum(i + 1) >= xとなるような最小のi
  int lower_bound(int x) {
    int i = -1;
    for (int w = max_pow; w > 0; w /= 2) {
      if (i + w < N && bit[i + w] < x) {
        x -= bit[i + w];
        i += w;
      }
    }
    return i + 1;
  }
  // query[begin, i + 1) >= xとなるような最小のi
  int lower_bound(int begin, int x) {
    int lb = lower_bound(x + sum(begin));
    return max(begin, lb);
  }
  // sum(i + 1) > xとなるような最小のi
  int upper_bound(int x) {
    int i = -1;
    for (int w = max_pow; w > 0; w /= 2) {
      if (i + w < N && bit[i + w] <= x) {
        x -= bit[i + w];
        i += w;
      }
    }
    return i + 1;
  }
  // query[begin, i + 1) > xとなるような最小のi
  int upper_bound(int begin, int x) {
    int ub = upper_bound(x + sum(begin));
    return max(begin, ub);
  }
};

int lis(const vector<int>& a) {
  vector<int> dp(a.size(), 1e17);
  REP (i, a.size()) {
    *lower_bound(ALL(dp), a[i]) = a[i];
  }
  return lower_bound(ALL(dp), 1e17) - dp.begin();
}
signed main() {
  int n; cin >> n;
  vector<int> a(n); REP (i, n) cin >> a[i], a[i] = -a[i];
  reverse(ALL(a));
  vector<int> dp(n, 1e17);
  vector<int> sum(n);
  int l = lis(a);
  dump(l);
  int ma = 0;
  int ans = 0;
  REP (i, n) {
    int idx = lower_bound(ALL(dp), a[i]) - dp.begin();
    dp[idx] = a[i];
    chmax(sum[idx], (idx == 0 ? 0 : sum[idx - 1]) - a[i]);
    if (idx + 1 == l) {
      dump(idx, sum[idx]);
      chmax(ans, sum[idx]);
    }
  }
  cout << ans << endl;
}



Measured memory_bytes: 5988