import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.nextLine();
		if (s.isEmpty()) {
			System.out.println("");
		} else {
			String ans = "";
			boolean check = true;
			for (int i = 0; i < s.length(); i++) {
				char ch1 = s.charAt(i);
				if (i > 0 && ch1 == 'B') {
					if (!ans.isEmpty())
						ans = ans.substring(0, ans.length() - 1);
					if (ans.isEmpty()) {
						ans = "";
					}
				} else {
					if (ch1 != 'B')
						ans += ch1;
				}
			}
			if (check) {
				System.out.println(ans);
			}
		}
	}
}
/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