import java.util.*;
class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int a = Integer.parseInt(sc.next()),b=Integer.parseInt(sc.next());
        if(a!=1&&b!=1){
            System.out.println(1);
        }else if(a!=2&&b!=2){
            System.out.println(2);
}else if(a!=3&&b!=3){
    System.out.println(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