import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		try {
			String s = sc.nextLine();
			StringBuilder sb = new StringBuilder(s);

			int index = sb.indexOf("B");
			while (true) {
				if (index == -1) {
					break;
				}

				sb = sb.deleteCharAt(index);
				if (index != 0) {
					sb = sb.deleteCharAt(index - 1);
				}

				index = sb.indexOf("B");
			}

			System.out.println(sb.toString());

		} finally {
			sc.close();
		}
	}
}
/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