#include<stdio.h>
int n,m,i,j,k;
int a[100001];
int b[100001];
int c[100001];
int main()
{
 freopen("cmlsc.in","r",stdin);
 freopen("cmlsc.out","w",stdout);
 scanf("%d%d",&n,&m);
       k=0;
 for(i=1;i<=n;i++)
	scanf("%d",&a[i]);
 for(i=1;i<=m;i++)
	scanf("%d",&b[i]);
 for(i=1;i<=n;i++)
	for(j=1;j<=m;j++)
		if(a[i]==b[j])
			c[++k]=a[i];
 printf("%d\n",k);
 for(i=1;i<=k;i++)
	printf("%d ",c[i]);
 return 0;
}