import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		char[] ch = sc.next().toCharArray();
		sc.close();

		StringBuilder sb = new StringBuilder();
		for(int i = 0;i < ch.length;i++) {
			if(sb.length()==0&&ch[i]=='B') {
				continue;
			}else if(sb.length() > 0&&ch[i]=='B') {
				sb.deleteCharAt(sb.length()-1);
			}else {
				sb.append(ch[i]);
			}
		}
		System.out.println(sb.toString());
	}
}
/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