import java.util.Scanner;

public class Main {

    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        sc.close();

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        }

        System.out.println(sb.toString());
    }
} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        sc.close();

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        }

        System.out.println(sb.toString());
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        sc.close();

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        }

        System.out.println(sb.toString());
    } main {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        sc.close();

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        }

        System.out.println(sb.toString());
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc sc.close() sc.close sc StringBuilder sb = new StringBuilder(); sb new StringBuilder() for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.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') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        } {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        } if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            } s.charAt(i) == '0' s.charAt(i) s.charAt s i '0' {
                sb.append("0");
            } sb.append("0") sb.append sb "0" if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            } s.charAt(i) == '1' s.charAt(i) s.charAt s i '1' {
                sb.append("1");
            } sb.append("1") sb.append sb "1" if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            } sb.length() != 0 sb.length() sb.length sb 0 {
                sb.deleteCharAt(sb.length() - 1);
            } sb.deleteCharAt(sb.length() - 1) sb.deleteCharAt sb sb.length() - 1 sb.length() sb.length sb 1 System.out.println(sb.toString()) System.out.println System.out System System.out sb.toString() sb.toString sb String[] args args public class Main {

    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        sc.close();

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        }

        System.out.println(sb.toString());
    }
} public class Main {

    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        sc.close();

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        }

        System.out.println(sb.toString());
    }
} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();

        sc.close();

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) == '0') {
                sb.append("0");
            } else if (s.charAt(i) == '1') {
                sb.append("1");
            } else if (sb.length() != 0) {
                sb.deleteCharAt(sb.length() - 1);
            }
        }

        System.out.println(sb.toString());
    }
}