#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>;

// 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;

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; }

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), sum(n + 1, -1);
  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]);
  }
  REP (i, n + 1) {
    if (sum[i] == -1) {
      cout << sum[i - 1] << endl; return 0;
    }
  }
}

