import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String s = in.next();
        StringBuffer buffer = new StringBuffer();
        int position = -1;
        for (char c : s.toCharArray()) {
            if (c == 'B') {
                if (buffer.length() != 0) {
                    buffer.deleteCharAt(position--);
                }
            } else {
                buffer.insert(++position, c);
            }
        }
        System.out.println(buffer);
    }
}
/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