import java.util.*;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// get a integer
		String N = sc.next();
		String output = "";
		
		for (int i = 0; i < N.length(); i++) {
			int output_size = output.length();
			if(N.charAt(i) == 'B') {
				if(output_size > 0) {
					output = output.substring(0, output_size - 1);
				}
			} else {
				output = output + N.substring(i, i+1); 
			}
			
		}
				
		// output
		System.out.println(output);
	}
}
/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