import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException {
		BufferedReader input =new BufferedReader (new InputStreamReader (System.in));
		String str = input.readLine( );
		String answer = "";

		for(int i=0; i<str.length(); i++){
			if(String.valueOf(str.charAt(i)).equals("B") && answer.length() != 0){
				answer = answer.substring(0, answer.length()-1);
			}else if(String.valueOf(str.charAt(i)).equals("0") || String.valueOf(str.charAt(i)).equals("1")){
				answer = answer + str.charAt(i);
			}
		}

		System.out.println(answer);
	}

}

/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