import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    while(true){
      String tmp = str.replace("1B", "").replace("0B", "");
      if(tmp.equals(str)){
        break;
      }
      str = tmp;
    }
    System.out.println(str.replace("B", ""));
  }
}
/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