import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int Bstock =0;
    String ans = "";
    for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    }
    System.out.println(ans);
        
  }
  

  
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int Bstock =0;
    String ans = "";
    for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    }
    System.out.println(ans);
        
  }
  

  
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int Bstock =0;
    String ans = "";
    for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    }
    System.out.println(ans);
        
  } main {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int Bstock =0;
    String ans = "";
    for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    }
    System.out.println(ans);
        
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc int Bstock =0; Bstock 0 String ans = ""; ans "" for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    } int i=s.length()-1; int i=s.length()-1; i s.length()-1 s.length() s.length s 1 i>=0 i 0 i-- i-- i {
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    } {
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    } if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      } s.substring(i,i+1).equals("B") s.substring(i,i+1).equals s.substring(i,i+1) s.substring s i i+1 i 1 "B" {
        Bstock++;
      } Bstock++ Bstock if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      } Bstock>0 Bstock 0 {
        Bstock--;
      } Bstock-- Bstock {
        ans=s.substring(i,i+1)+ans;
      } ans=s.substring(i,i+1)+ans ans s.substring(i,i+1)+ans s.substring(i,i+1) s.substring s i i+1 i 1 ans System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int Bstock =0;
    String ans = "";
    for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    }
    System.out.println(ans);
        
  }
  

  
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int Bstock =0;
    String ans = "";
    for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    }
    System.out.println(ans);
        
  }
  

  
} Main
import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int Bstock =0;
    String ans = "";
    for(int i=s.length()-1;i>=0;i--){
      if(s.substring(i,i+1).equals("B")){
        Bstock++;
      }else if(Bstock>0){
        Bstock--;
      }else{
        ans=s.substring(i,i+1)+ans;
      }
    }
    System.out.println(ans);
        
  }
  

  
}