import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner scanner = new Scanner(System.in);
		String input = scanner.nextLine();
		String[] inputs = input.split("");
		List<String> line = new ArrayList<String>();
		for(String c : inputs){
			if(c.equals("0") || c.equals("1")){
				line.add(c);
			}else{
				if(!line.isEmpty()){
					line.remove(line.size()-1);
				}
			}
		}
		System.out.println(String.join("", line));
	}

}

/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