
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
      String s=sc.nextLine();

int a=Integer.parseInt(s);
       s=sc.nextLine();
      
int b=Integer.parseInt(s);


int[] data={1,2,3};
for(int i=0;i<3;i++){
if(data[i]==a)data[i]=0;
if(data[i]==b)data[i]=0;

}

for(int i=0;i<3;i++){
if(data[i]!=0)
System.out.println(data[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