import java.io.*;
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
 
      String[] t=sc.nextLine().split("");
//    String nyuA=sc.nextLine();
//   String nyu=sc.nextLine();

//int n=Integer.parseInt(nyu);

//int A=Integer.parseInt(t[0]);
//int B=Integer.parseInt(t[1]);
String tem="";
for(int i=0;i<t.length;i++){
switch(t[i]){
case "0":
tem+="0";
break;
case "1":
tem+="1";
break;
case "B":
String[] te=tem.split("");
tem="";
for(int j=0;j<te.length-1;j++){
tem+=te[j];
}
break;
default:
break;

}//sw

}//for

System.out.println(tem);


	}
}
/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