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

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		ArrayList<String> b = new ArrayList<String>();
		for(int i=0 ; i<a.length() ; i++) {
			if(a.charAt(i) == '0') {
				b.add(a.substring(i, i+1));
			}
			else if(a.charAt(i) == '1') {
				b.add(a.substring(i, i+1));
			}
			else if(!b.isEmpty()) {
				b.remove((b.size()-1));
			}
		}
		for(int i=0 ; i<b.size() ; i++) {
			System.out.print(b.get(i));
		}
		System.out.println("");
	}
}
/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