#include <fstream>
#include <iostream>
using namespace std;
int v[100002],q[100002],p[100002],u;
int cautare(int x)
{
    int m;
    int first=1,last=u;
    while (first<=last)
    {
        int m=(first+last)/2;
        if (x>=q[m])
            first=m+1;
        if (x<q[m])
            last=m-1;
        return last;
    }
}
int main()
{
    int n,i,x;
    ifstream fin("scmax.in");
    ofstream fout("scmax.out");
    cin>>n;
    for (i=1; i<=n; i++)
    {
        cin>>v[i];
    }
    q[1]=v[1];
    p[1]=1;
    int u=1;
    for (i=2; i<=n; i++)
    {
        x=cautare(v[i]);
        if(x<=u) q[x]=v[i],p[i]=x;
        else q[u++]=v[i],p[i]=u;
    }
    cout<<u<<"\n";
    int o=u;
    for(i=1;i<=u;i++)
        cout<<q[i]<<" ";
    for (i=u; i>=1; i--)
    {
        if (p[i]==u)
        {
            q[u]=i;
            u--;
        }
    }
    for (i=1; i<=o; i++)
        cout<<v[q[i]]<<" ";
    return 0;
}