import java.io.*;

class Main{
	public static void main(String[] args){
		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
		try{
			String line = reader.readLine();
			int A = Integer.parseInt(line);
			line = reader.readLine();
			int B = Integer.parseInt(line);
			int result = 6 - (A + B);
			System.out.println(result);
		}catch(NumberFormatException e){
			e.printStackTrace();
			System.exit(0);
		}catch(IOException e){
			e.printStackTrace();
			System.exit(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