/*
 * Author: nskybytskyi
 * Time:   2022-01-07 14:20:00
 */

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

const int inf = numeric_limits<int>::max();

// https://cp-algorithms.com/sequences/longest_increasing_subsequence.html
vector<int> lis(vector<int> const& a) {
  int n = a.size();
  vector<int> d(n + 1, inf), ends(n);
  d[0] = -inf;

  for (int i = 0; i < n; ++i) {
    int j = distance(d.begin(), upper_bound(d.begin(), d.end(), a[i]));
    ends[i] = j;
    if (d[j - 1] < a[i] && a[i] < d[j]) {
      d[j] = a[i];
    }
  }

  return ends;
}

int main() {
  cin.tie(0)->sync_with_stdio(0);

  int n;
  cin >> n;

  vector<int> p(n);
  for (auto& pi : p) {
    cin >> pi;
  }

  auto ends = lis(p);

  for (auto& pi : p) {
    pi = -pi;
  }
  reverse(p.begin(), p.end());

  auto begins = lis(p);
  reverse(begins.begin(), begins.end());

  for (auto& pi : p) {
    pi = -pi;
  }
  reverse(p.begin(), p.end());

  const int mx = *max_element(ends.begin(), ends.end());

  vector<vector<int>> elems(mx + 1);

  for (int i = 0; i < n; ++i) {
    if (begins[i] + ends[i] == mx + 1) {
      elems[begins[i]].push_back(p[i]);
    }
  }

  set<int> unique;

  for (const auto& vec_elem : elems) {
    if (vec_elem.size() == 1) {
      unique.insert(vec_elem[0]);
    }
  }

  cout << unique.size() << "\n";
  for (auto elem : unique) {
    cout << elem << " ";
  }
  cout << "\n";

  return 0;
}