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

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		sc.close();
		List<String> list = new ArrayList<String>();
		for(int i = 0; i < s.length(); i++) {
			if(s.charAt(i) == 'B') {
					if(list.size() > 0) {
						list.remove(list.size() - 1);
					}
			}else {
				list.add(String.valueOf(s.charAt(i)));
			}
		}
		StringBuilder sb = new StringBuilder();
		for(String t : list) {
			sb.append(t);
		}
		System.out.println(sb.toString());
	}
}
/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