#include<iostream>
using namespace std;
#define maxn 500+5
int test,n,m;
int f[maxn][maxn],s[maxn][maxn];
int a[maxn],b[maxn],ans[maxn];

int main()
{
    int i,j,k,p,Max,I,J,now;
    test=1;
    while (test--) {
        scanf("%d",&n);
        for (i=1; i<=n; i++) scanf("%d",&a[i]);
        scanf("%d",&m);
        for (i=1; i<=m; i++) scanf("%d",&b[i]);        
        /*f[i][j]表示a[1..i]，与b[j]匹配最长长度*/
        Max=I=J=0;
        for (i=1; i<=n; i++)
            for (j=1; j<=m; j++) {
                f[i][j]=f[i-1][j];
                s[i][j]=-1;
                if (a[i]==b[j]) {
                    p=0;
                    for (k=1; k<j; k++) if (b[k]<b[j] && f[i-1][k]>f[i-1][p]) p=k;
                    if (f[i-1][p]+1>f[i][j]) {
                        f[i][j]=f[i-1][p]+1;
                        s[i][j]=p;
                    }
                }
                if (f[i][j]>Max) {
                    Max=f[i][j];
                    I=i; J=j;
                }
            }
        printf("%d\n",Max);
        now=Max;
        while (now) {
            if (s[I][J]>-1) {
                ans[now--]=b[J];
                J=s[I][J];
            }
            I--;
        }
        for (i=1; i<Max; i++) printf("%d ",ans[i]);
        printf("%d\n",ans[Max]);
    }
    return 0;
}