import java.util.*;
 
public class Main {
 
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		String ans = "";
		for (char c : S.toCharArray()) {
			if (c == '0') {
				ans += "0";
			} else if (c == '1') {
				ans += "1";
			} else if (c == 'B' && ans.length() == 0) {
				continue;
			} else {
				ans = ans.substring(0, ans.length()-1);
			}
		}
		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