import java.util.Scanner;
import java.util.LinkedList;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
  	LinkedList<Character> stack = new LinkedList<>();
    String s = sc.next();
    String res = "";
    
    for (int i = 0; i < s.length(); i++) {
    	if (s.charAt(i) == 'B') {
          if (!stack.isEmpty()) {
          	stack.pop();
          }
        } else {
        	stack.push(s.charAt(i));
        }
    }
                       
    while (!stack.isEmpty()) {
      res = stack.pop() + res;
    }
                       
    System.out.println(res);
  }
}

/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