import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Main main = new Main();
		main.solve();
	}

	void solve() {
		Scanner sc = new Scanner(System.in);
		char[] C = sc.next().toCharArray();
		String S = "";
		sc.close();
		for(int i=0;i<C.length;i++) {
			if(C[i]=='B') {if(S.length()>0)S=S.substring(0, S.length()-1);}
			else S+=C[i];
		}
		System.out.println(S);
	}
}

/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