import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		String tempStr = "";
		String ansStr = "";
		for (int i = 0; i < s.length(); i++) {
			tempStr = s.substring(i, i + 1);
			if (tempStr.equals("0") | tempStr.equals("1")) {
				ansStr += tempStr;
			} else {
				if (ansStr.equals("")) {
					continue;
				} else {
					ansStr = ansStr.substring(0, ansStr.length() - 1);
				}
			}
		}
		System.out.println(ansStr);
	}
}
/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