import java.util.Scanner;

public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    int A = scan.nextInt();
    int B = scan.nextInt();
    if(A != 1 && B != 1){
      System.out.print(1);
    }
    else if(A != 2 && B != 2){
      System.out.print(2);
    }
    else if(A != 3 && B != 3){
      System.out.print(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