import java.util.Scanner;

public class Main{
    public static void main(String[] args){
	Scanner scan = new Scanner(System.in);

	/* 入力 */
	String s = scan.next();

	String ans = "";
	for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	}

	/* 出力 */
	System.out.println(ans);
    }
} import java.util.Scanner; Scanner java.util public class Main{
    public static void main(String[] args){
	Scanner scan = new Scanner(System.in);

	/* 入力 */
	String s = scan.next();

	String ans = "";
	for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	}

	/* 出力 */
	System.out.println(ans);
    }
} Main public static void main(String[] args){
	Scanner scan = new Scanner(System.in);

	/* 入力 */
	String s = scan.next();

	String ans = "";
	for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	}

	/* 出力 */
	System.out.println(ans);
    } main {
	Scanner scan = new Scanner(System.in);

	/* 入力 */
	String s = scan.next();

	String ans = "";
	for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	}

	/* 出力 */
	System.out.println(ans);
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String s = scan.next(); s scan.next() scan.next scan String ans = ""; ans "" for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	} int i = 0; int i = 0; i 0 i < s.length() i s.length() s.length s i++ i++ i {
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	} {
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	} if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    } s.charAt(i) == '0' s.charAt(i) s.charAt s i '0' {
		ans += "0";
	    } ans += "0" ans "0" if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    } s.charAt(i) == '1' s.charAt(i) s.charAt s i '1' {
		ans += "1";
	    } ans += "1" ans "1" {
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    } if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		} ans.length() != 0 ans.length() ans.length ans 0 {
		    ans = ans.substring(0,ans.length()-1);
		} ans = ans.substring(0,ans.length()-1) ans ans.substring(0,ans.length()-1) ans.substring ans 0 ans.length()-1 ans.length() ans.length ans 1 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 scan = new Scanner(System.in);

	/* 入力 */
	String s = scan.next();

	String ans = "";
	for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	}

	/* 出力 */
	System.out.println(ans);
    }
} public class Main{
    public static void main(String[] args){
	Scanner scan = new Scanner(System.in);

	/* 入力 */
	String s = scan.next();

	String ans = "";
	for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	}

	/* 出力 */
	System.out.println(ans);
    }
} Main
import java.util.Scanner;

public class Main{
    public static void main(String[] args){
	Scanner scan = new Scanner(System.in);

	/* 入力 */
	String s = scan.next();

	String ans = "";
	for(int i = 0; i < s.length(); i++){
	    if(s.charAt(i) == '0'){
		ans += "0";
	    }else if(s.charAt(i) == '1'){
		ans += "1";
	    }else{
		if(ans.length() != 0){
		    ans = ans.substring(0,ans.length()-1);
		}
	    }
	}

	/* 出力 */
	System.out.println(ans);
    }
}
