#include <fstream>
#include <set>
#define nmax 100004
using namespace std;
ifstream f("scmax.in");
ofstream g("scmax.out");
int n,v[nmax];
set <int> q;
int main()
{
    f>>n;
    for (int i=1;i<=n;i++) f>>v[i];
    q.insert(v[1]);
    for (int i=2;i<=n;i++)
    {
        if (*q.upper_bound(v[i])!=*q.end())
        {
            q.erase(q.upper_bound(v[i]));
            q.insert(v[i]);
        }
        else q.insert(v[i]);
    }
    g<<q.size()<<'\n';
    for (auto i:q) g<<i<<' ';
    f.close();
    g.close();
    return 0;
}