import java.util.*;

public class Main{
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);
        
        String s = sc.next();
        sc.close();

        List<Character> str = new ArrayList<>();
        for(int i = 0; i < s.length(); i++){
            if(s.charAt(i) == '0')
                str.add('0');
            else if(s.charAt(i) == '1')
                str.add('1');
            else{
                if(str.size() != 0)
                    str.remove(str.size()-1);
            }
        }
        for(int i = 0; i < str.size(); i++){
            System.out.print(str.get(i));
        }
    }
}
/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