import java.util.ArrayList;
import java.util.List;
import java.util.Collections;
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner scan =new Scanner(System.in);
		while(scan.hasNext()){
			int n=scan.nextInt();
			int m=scan.nextInt();
			if(n==0&&m==0)break;
			List<Integer> a=new ArrayList<Integer>();
			List<Integer> b=new ArrayList<Integer>();
			for(int i=1;i<=n;i++){
				int s=scan.nextInt();
				a.add(s);
			}
            for(int i=1;i<=m;i++){
            	int s=scan.nextInt();
            	b.add(s);
			}
            a.removeAll(b);
            Collections.sort(a);
            if(a.isEmpty())
            	System.out.println("NULL");
            else {
            	for(int i=0;i<a.size();i++)
            	        {System.out.print(a.get(i)+" ");}
            	System.out.println();
            	        }			
		}
	}
}