import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char s[] = sc.next().toCharArray();
        sc.close();
        Deque<Integer> q = new ArrayDeque<>();
        for (char x : s) {
            if (q.isEmpty()) {
                if (x != 'B') {
                    q.add(x - 48);
                }
            } else if (x == 'B') {
                q.pollLast();
            } else {
                q.add(x - 48);
            }
        }
        for (int i : q) {
            System.out.print(i);
        }
        System.out.println();
    }
}
/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