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

    public class Main extends PrintWriter {
        Main() { super(System.out, true); }
        Scanner sc = new Scanner(System.in);
        public static void main(String[] $) {
            Main o = new Main(); o.main(); o.flush();
        }

        void main(){
            int A = Integer.parseInt(sc.next());
            int B = Integer.parseInt(sc.next());

            if(A != 1 && B != 1){
                print('1');
        }
            if(A != 2 && B != 2){
                print('2');
            }
            if(A != 3 && B != 3){
                print('3');
            }
    }
}

/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