#include <stdio.h>

int a[100002],s1[100002],s2[100002];
int n,lg;

void citire()
{
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
}

void rezolvare()
{
    int i,j;
    bool ok;
    for(i=1;i<=n;i++)
    {
        for(j=0,ok=false;!ok&&j<lg;j++)
        {
            if(s1[j]>a[i])
            {
                s1[j]=a[i];
                s2[i]=j;
                ok=true;
            }
            else if(s1[j]==a[i])ok=true;
        }
        if(!ok)
          s1[lg]=a[i],s2[i]=lg++;
       }
    }

void afisare()
{
    printf("%d\n",lg);
    int k=0;
    lg--;
    while(lg>=0)
    {
        if(s2[n]==lg)
        {
            s1[++k]=a[n];
            lg--;
        }
        n--;
    }
    while(k)
        printf ("%d ",s1[k--]);
}

int main ()
{
    freopen ("scmax.in","r",stdin);
    freopen ("scmax.out","w",stdout);
    scanf("%d",&n);
    citire();
    rezolvare();
    afisare();
    return 0;
}