#include <bits/stdc++.h>

using namespace std;

ifstream fin("scmax.in");
ofstream fout("scmax.out");

set<int> SCLM(vector<int> v){
    set<int> s;
    for(int i = 0; i < v.size(); ++i){
        s.insert(v[i]);
        auto it = s.upper_bound(v[i]);
        if(it != s.end())
            s.erase(it);
    }
    return s;
}

vector<int> v;

int main()
{
    int n;
    fin >> n;

    for(int i = 1; i <= n; ++i)
    {
        int a;
        fin >> a;

        v.push_back(a);
    }

    auto rez = SCLM(v);
    fout << rez.size() << '\n';
    for(auto it: rez)
        fout << it << ' ';
    return 0;
}