import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
       Scanner in=new Scanner(System.in);
       int a,b,c;
       a=in.nextInt();
       b=in.nextInt();
        for (int i = 1; i <=3; i++) {
            if(i!=a && i!=b){
                System.out.println(i);
            }
        }
    }
    
}
/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