import java.util.*;
public class Main {
    
    static void solve(){
        Scanner sc = new Scanner(System.in);
        StringBuilder s = new StringBuilder();
        for (char ch : sc.next().toCharArray()) {
            int len = s.length();
            if(ch!='B') s.append(ch); 
            else if(len>0) s=new StringBuilder(s.toString().substring(0,len-1));
        }
        System.out.println(s);
        sc.close();
    }
    
    public static void main(String args[]) {
        solve();
    }

}   

/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