import java.io.*;
import java.util.*;
public class Q_2034 {
public static void main(String args[]){
Scanner in = new Scanner(new BufferedInputStream(System.in));
while(in.hasNext()){
int n = in.nextInt();
int m = in.nextInt();
if(n == 0 && m == 0)
break;
else{
int a[][] = new int[2][n];
int b[] = new int[m];
int t=0,x=0;
for(int i = 0;i<m+n;i++)
if(i<n)
a[0][i] = in.nextInt();
else
b[i-n] = in.nextInt();
for(int i=0;i<n;i++)
for(int j = 0;j<m;j++){
if(a[0][i] == b[j]){
a[1][i] = 1;
}
}
for(int i=0;i<n;i++)
if(a[1][i] != 1){
t++;
}
int c[] = new int[t];
for(int i=0;i<n;i++)
if(a[1][i] != 1){
c[x] = a[0][i];
x++;
}
Arrays.sort(c);
for(int i=0;i<t;i++)
System.out.print(c[i]+" ");
if(t == 0)
System.out.print("NULL");
System.out.println();
}
}
}
}