import java.util.*;

public class Main {

  public static void main (String[] args) {

    Scanner sc = new Scanner(System.in);

    String s = sc.next();

    sc.close();

    String[] S = s.split("");
    
    Deque<String> deque = new ArrayDeque<>();

    for (int i = 0; i < S.length; i++) {
      if (S[i].equals("0")) {
        deque.addLast("0");
      }
      if (S[i].equals("1")) {
        deque.addLast("1");
      }
      if (S[i].equals("B")) {
        if (0 < deque.size()) {
          deque.pollLast();
        }
      }
    }

    int l = deque.size();

    for (int i = 0; i < l; i++) {
      System.out.print(deque.pollFirst());
    }

    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