//https://www.infoarena.ro/problema/scmax
#include <bits/stdc++.h>
using namespace std;

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

int v[100010],d[1000010],ret[1000010];
int main()
{
    int n,i;
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>v[i];
    }
    d[1]=v[1];
    int l=0,k;
    for(i=2;i<=n;i++)
    {
        if(d[l]!=v[i])
        {
            if(d[l]<v[i])
            {
                l++;
                d[l]=v[i];
            }
            int st=1,dr=l;
            while(st<=dr)
            {
                int mij=(st+dr)/2;
                if(v[i]<d[mij])
                {
                    k=mij;
                    dr=mij-1;
                }
                else
                {
                    st=mij+1;
                }
            }
            d[k]=v[i];
            ret[i]=k;
        }

    }
    fout<<l<<"\n";
    for(i=1;i<=l;i++)
    {
        fout<<d[i]<<" ";
    }

    return 0;
}