
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		List<Integer> list = new ArrayList<>();
		
		list.add(1);
		list.add(2);
		list.add(3);
		
		
		list.remove(list.indexOf(scan.nextInt()));
		list.remove(list.indexOf(scan.nextInt()));
		
		System.out.println(list.get(0));
	
	}
}
/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