import java.io.*;
import java.util.*;

class Main{
    public static void main(String args[])throws IOException{
      try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))){
        List<Integer> list = new ArrayList<>(Arrays.asList(1,2,3));
        List<Integer> remove = new ArrayList<>();

        int a = Integer.parseInt(br.readLine());
        int b = Integer.parseInt(br.readLine());
        Collections.addAll(remove, a,b);
        
        list.removeAll(remove);

        for (Integer integer : list) {
          System.out.println(integer);
        }
      }

    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz