比较重复元素太笨了

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        while(scan.hasNext()){
            
            int n1 = scan.nextInt();
            int[] nums1 = new int[n1];
            for(int i= 0; i<n1; i++){
                nums1[i] = scan.nextInt();
            }
            int n2 = scan.nextInt();
            int[] nums2 = new int[n2];
            for(int i = 0; i<n2; i++){
                nums2[i] = scan.nextInt();
            }
            
            List<Integer> list = new ArrayList<>();
            
            for(int i : nums1){
                int count = 0;
                for(int j = 0; j<list.size(); j++){
                    if(list.get(j)!=i){
                        count++;
                    }
                }
                if(count == list.size()){
                    list.add(i);
                }
            }
            for(int i : nums2){
                int count = 0;
                for(int j : nums1){
                    if( j!=i){
                        count++;
                    }
                }
                if(count == nums1.length){
                    list.add(i);
                }
            }
            list.sort(Comparator.naturalOrder());
            for(int i =0; i<list.size(); i++){
                System.out.print(list.get(i));
            }
            
            
        }
        scan.close();
    }
}