import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		// 文字列の入力
		String[] s = sc.next().split("");
        ArrayList<String> list = new ArrayList<>();
        for(int i = 0; i < s.length; i++) {
          if (s[i].equals("B")) {
            if (list.size() > 0) {
             list.remove(list.size() - 1);
            }
          } else {
            list.add(s[i]);
          }
        }
        String ans = "";
        for(String word : list) {
          ans+= word;
        }
      
		// 出力
		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