#include<fstream>
#include<iostream>
using namespace std;

const int Nmax = 1024;

ifstream f("cmlsc.in");
ofstream g("cmlsc.out");

int a[Nmax],b[Nmax],c[Nmax][Nmax],d[Nmax], n, m, k = 0;
void read()
{
    int i,j;
    f >> n >>m;
    for(i=1;i<=n;i++)
        f>>a[i];
    for(j=1;j<=m;j++)
        f>>b[i];
}
void solve()
{
    int i,j;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++)
            if(a[i]==b[j])
                c[i][j]=c[i-1][j-1]+1;
            else
                c[i][j]=max(c[i-1][j],c[i][j-1]);

    g<<c[n][m]<<endl;
}
void print(int i,int j)
{
    while(i>0 && j>0)
    {
        if(a[i]==b[j])
        {
            d[++k] = a[i];
            i--;
            j--;
        }
        else
        {
            if(c[i-1][j]<c[i][j-1])
                j--;
            else
                i--;
        }
    }
    for(i = k;i >= 1;i --)
        g<< d[i] <<" ";
}
int main()
{
    read();
    solve();
    print(n,m);
    return 0;
}