#include <fstream>  
using namespace std;  
	
int main()  
{  
	ifstream fin("cmlsc.in");  
	int a[1024] , b[1024], c[1024];  
	int m, n, p, i, j, nr;  
         
	fin >> n >> m;  
         
	for ( i = 0; i < n; i++)  
		fin >> a[i];  
	for ( j = 0; j < m; j++)  
		fin >> b[j];  
		fin.close();  
         
	ofstream fout("cmlsc.out");  
	p = 0; nr = 0;  
	int gasit;  
	for ( i = 0; i < n; i++)  
	{  
		gasit = 0;  
		for ( j = 0; j < m; j++)  
			if ( a[i] == b[j] )  
			{  
				gasit = 1;  
				nr++;    
			}  
		if (gasit)  
		c[p++] = a[i];  
	}  
       fout << nr << '\n';  
     for ( i = 0; i < p; i++)  
           fout << c[i] << ' ';  
           fout.close();  
           return 0;  
  }