import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		sc.close();
		int c=0;
		if(a==1 && b==2 || a==2 && b==1) {
			c=3;
		}else if(a==1 && b==3 || a==3 && b==1) {
			c=2;
		}else if(a==3 && b==2 || a==2 && b==3) {
			c=1;
		}
		System.out.println(c);
	}

}
/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