import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Stack;

public class Main {
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";

    static void solve()
    {
        String s = ns();
        Stack<Character> stack = new Stack<>();
        for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        }
        StringBuilder res = new StringBuilder();
        while (!stack.isEmpty()) {
            res.append(stack.pop());
        }

        System.out.println(res.reverse());
    }

    public static void main(String[] args) throws Exception
    {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    }

    private static boolean eof()
    {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }

    private static byte[] inbuf = new byte[1024];
    static int lenbuf = 0, ptrbuf = 0;

    private static int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }

    private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }

    private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

    private static double nd() { return Double.parseDouble(ns()); }
    private static char nc() { return (char)skip(); }

    private static String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private static char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private static char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }

    private static int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }

    private static int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
}
 import java.io.ByteArrayInputStream; ByteArrayInputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Arrays; Arrays java.util import java.util.InputMismatchException; InputMismatchException java.util import java.util.Stack; Stack java.util public class Main {
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";

    static void solve()
    {
        String s = ns();
        Stack<Character> stack = new Stack<>();
        for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        }
        StringBuilder res = new StringBuilder();
        while (!stack.isEmpty()) {
            res.append(stack.pop());
        }

        System.out.println(res.reverse());
    }

    public static void main(String[] args) throws Exception
    {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    }

    private static boolean eof()
    {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }

    private static byte[] inbuf = new byte[1024];
    static int lenbuf = 0, ptrbuf = 0;

    private static int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }

    private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }

    private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

    private static double nd() { return Double.parseDouble(ns()); }
    private static char nc() { return (char)skip(); }

    private static String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private static char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private static char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }

    private static int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }

    private static int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
} Main static InputStream is; is static PrintWriter out; out static String INPUT = ""; INPUT "" private static byte[] inbuf = new byte[1024]; inbuf new byte[1024] 1024 static int lenbuf = 0 lenbuf 0 ptrbuf = 0; ptrbuf 0 static void solve()
    {
        String s = ns();
        Stack<Character> stack = new Stack<>();
        for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        }
        StringBuilder res = new StringBuilder();
        while (!stack.isEmpty()) {
            res.append(stack.pop());
        }

        System.out.println(res.reverse());
    } solve {
        String s = ns();
        Stack<Character> stack = new Stack<>();
        for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        }
        StringBuilder res = new StringBuilder();
        while (!stack.isEmpty()) {
            res.append(stack.pop());
        }

        System.out.println(res.reverse());
    } String s = ns(); s ns() ns Stack<Character> stack = new Stack<>(); stack new Stack<>() for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        } Character c s.toCharArray() s.toCharArray s {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        } {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        } if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            } c == '0' c '0' {
                stack.push(c);
            } stack.push(c) stack.push stack c if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            } c == '1' c '1' {
                stack.push(c);
            } stack.push(c) stack.push stack c if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            } c == 'B' c 'B' {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            } if (!stack.isEmpty()) {
                    stack.pop();
                } !stack.isEmpty() stack.isEmpty() stack.isEmpty stack {
                    stack.pop();
                } stack.pop() stack.pop stack StringBuilder res = new StringBuilder(); res new StringBuilder() while (!stack.isEmpty()) {
            res.append(stack.pop());
        } !stack.isEmpty() stack.isEmpty() stack.isEmpty stack {
            res.append(stack.pop());
        } res.append(stack.pop()) res.append res stack.pop() stack.pop stack System.out.println(res.reverse()) System.out.println System.out System System.out res.reverse() res.reverse res public static void main(String[] args) throws Exception
    {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    } main {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    } long S = System.currentTimeMillis(); S System.currentTimeMillis() System.currentTimeMillis System is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()) is INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()) INPUT.isEmpty() INPUT.isEmpty INPUT System.in System System.in new ByteArrayInputStream(INPUT.getBytes()) out = new PrintWriter(System.out) out new PrintWriter(System.out) solve() solve out.flush() out.flush out long G = System.currentTimeMillis(); G System.currentTimeMillis() System.currentTimeMillis System tr(G-S+"ms") tr G-S+"ms" G-S G S "ms" String[] args args private static boolean eof()
    {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    } eof {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    } if(lenbuf == -1)return true; lenbuf == -1 lenbuf -1 1 return true; true int lptr = ptrbuf; lptr ptrbuf while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false; lptr < lenbuf lptr lenbuf if(!isSpaceChar(inbuf[lptr++]))return false; !isSpaceChar(inbuf[lptr++]) isSpaceChar(inbuf[lptr++]) isSpaceChar inbuf[lptr++] inbuf lptr++ lptr return false; false try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        } catch (IOException e) {
            return true;
        } IOException e {
            return true;
        } return true; true {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } is.mark(1000) is.mark is 1000 while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            } true {
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            } int b = is.read(); b is.read() is.read is if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                } b == -1 b -1 1 {
                    is.reset();
                    return true;
                } is.reset() is.reset is return true; true if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                } !isSpaceChar(b) isSpaceChar(b) isSpaceChar b {
                    is.reset();
                    return false;
                } is.reset() is.reset is return false; false private static int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    } readByte {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    } if(lenbuf == -1)throw new InputMismatchException(); lenbuf == -1 lenbuf -1 1 throw new InputMismatchException(); new InputMismatchException() if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        } ptrbuf >= lenbuf ptrbuf lenbuf {
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        } ptrbuf = 0 ptrbuf 0 try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } catch (IOException e) { throw new InputMismatchException(); } IOException e { throw new InputMismatchException(); } throw new InputMismatchException(); new InputMismatchException() { lenbuf = is.read(inbuf); } lenbuf = is.read(inbuf) lenbuf is.read(inbuf) is.read is inbuf if(lenbuf <= 0)return -1; lenbuf <= 0 lenbuf 0 return -1; -1 1 return inbuf[ptrbuf++]; inbuf[ptrbuf++] inbuf ptrbuf++ ptrbuf private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } isSpaceChar { return !(c >= 33 && c <= 126); } return !(c >= 33 && c <= 126); !(c >= 33 && c <= 126) (c >= 33 && c <= 126) c >= 33 c 33 c <= 126 c 126 int c c private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } skip { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } int b; b while((b = readByte()) != -1 && isSpaceChar(b)); (b = readByte()) != -1 && isSpaceChar(b) (b = readByte()) != -1 (b = readByte()) b readByte() readByte -1 1 isSpaceChar(b) isSpaceChar b return b; b private static double nd() { return Double.parseDouble(ns()); } nd { return Double.parseDouble(ns()); } return Double.parseDouble(ns()); Double.parseDouble(ns()) Double.parseDouble Double ns() ns private static char nc() { return (char)skip(); } nc { return (char)skip(); } return (char)skip(); (char)skip() skip private static String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    } ns {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    } int b = skip(); b skip() skip StringBuilder sb = new StringBuilder(); sb new StringBuilder() while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        } !(isSpaceChar(b)) (isSpaceChar(b)) isSpaceChar b {
            sb.appendCodePoint(b);
            b = readByte();
        } sb.appendCodePoint(b) sb.appendCodePoint sb b b = readByte() b readByte() readByte return sb.toString(); sb.toString() sb.toString sb private static char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    } ns {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    } char[] buf = new char[n]; buf new char[n] n int b = skip() b skip() skip p = 0; p 0 while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        } p < n && !(isSpaceChar(b)) p < n p n !(isSpaceChar(b)) (isSpaceChar(b)) isSpaceChar b {
            buf[p++] = (char)b;
            b = readByte();
        } buf[p++] = (char)b buf[p++] buf p++ p (char)b b = readByte() b readByte() readByte return n == p ? buf : Arrays.copyOf(buf, p); n == p ? buf : Arrays.copyOf(buf, p) n == p n p buf Arrays.copyOf(buf, p) Arrays.copyOf Arrays buf p int n n private static char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    } nm {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    } char[][] map = new char[n][]; map new char[n][] n for(int i = 0;i < n;i++)map[i] = ns(m); int i = 0; int i = 0; i 0 i < n i n i++ i++ i map[i] = ns(m); map[i] = ns(m) map[i] map i ns(m) ns m return map; map int n n int m m private static int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    } na {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    } int[] a = new int[n]; a new int[n] n for(int i = 0;i < n;i++)a[i] = ni(); int i = 0; int i = 0; i 0 i < n i n i++ i++ i a[i] = ni(); a[i] = ni() a[i] a i ni() ni return a; a int n n private static int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    } ni {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    } int num = 0 num 0 b; b boolean minus = false; minus false while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); (b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-') (b = readByte()) != -1 (b = readByte()) b readByte() readByte -1 1 !((b >= '0' && b <= '9') || b == '-') ((b >= '0' && b <= '9') || b == '-') (b >= '0' && b <= '9') b >= '0' b '0' b <= '9' b '9' b == '-' b '-' if(b == '-'){
            minus = true;
            b = readByte();
        } b == '-' b '-' {
            minus = true;
            b = readByte();
        } minus = true minus true b = readByte() b readByte() readByte while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        } true {
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        } if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            } b >= '0' && b <= '9' b >= '0' b '0' b <= '9' b '9' {
                num = num * 10 + (b - '0');
            } num = num * 10 + (b - '0') num num * 10 + (b - '0') num * 10 num 10 (b - '0') b '0' {
                return minus ? -num : num;
            } return minus ? -num : num; minus ? -num : num minus -num num num b = readByte() b readByte() readByte private static long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    } nl {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    } long num = 0; num 0 int b; b boolean minus = false; minus false while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); (b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-') (b = readByte()) != -1 (b = readByte()) b readByte() readByte -1 1 !((b >= '0' && b <= '9') || b == '-') ((b >= '0' && b <= '9') || b == '-') (b >= '0' && b <= '9') b >= '0' b '0' b <= '9' b '9' b == '-' b '-' if(b == '-'){
            minus = true;
            b = readByte();
        } b == '-' b '-' {
            minus = true;
            b = readByte();
        } minus = true minus true b = readByte() b readByte() readByte while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        } true {
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        } if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            } b >= '0' && b <= '9' b >= '0' b '0' b <= '9' b '9' {
                num = num * 10 + (b - '0');
            } num = num * 10 + (b - '0') num num * 10 + (b - '0') num * 10 num 10 (b - '0') b '0' {
                return minus ? -num : num;
            } return minus ? -num : num; minus ? -num : num minus -num num num b = readByte() b readByte() readByte private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); } tr { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); } if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); INPUT.length() != 0 INPUT.length() INPUT.length INPUT 0 System.out.println(Arrays.deepToString(o)) System.out.println System.out System System.out Arrays.deepToString(o) Arrays.deepToString Arrays o Object... o o public class Main {
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";

    static void solve()
    {
        String s = ns();
        Stack<Character> stack = new Stack<>();
        for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        }
        StringBuilder res = new StringBuilder();
        while (!stack.isEmpty()) {
            res.append(stack.pop());
        }

        System.out.println(res.reverse());
    }

    public static void main(String[] args) throws Exception
    {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    }

    private static boolean eof()
    {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }

    private static byte[] inbuf = new byte[1024];
    static int lenbuf = 0, ptrbuf = 0;

    private static int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }

    private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }

    private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

    private static double nd() { return Double.parseDouble(ns()); }
    private static char nc() { return (char)skip(); }

    private static String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private static char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private static char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }

    private static int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }

    private static int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
} public class Main {
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";

    static void solve()
    {
        String s = ns();
        Stack<Character> stack = new Stack<>();
        for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        }
        StringBuilder res = new StringBuilder();
        while (!stack.isEmpty()) {
            res.append(stack.pop());
        }

        System.out.println(res.reverse());
    }

    public static void main(String[] args) throws Exception
    {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    }

    private static boolean eof()
    {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }

    private static byte[] inbuf = new byte[1024];
    static int lenbuf = 0, ptrbuf = 0;

    private static int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }

    private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }

    private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

    private static double nd() { return Double.parseDouble(ns()); }
    private static char nc() { return (char)skip(); }

    private static String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private static char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private static char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }

    private static int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }

    private static int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
} Main
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Stack;

public class Main {
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";

    static void solve()
    {
        String s = ns();
        Stack<Character> stack = new Stack<>();
        for (Character c : s.toCharArray()) {
            if (c == '0') {
                stack.push(c);
            } else if (c == '1') {
                stack.push(c);
            } else if (c == 'B') {
                if (!stack.isEmpty()) {
                    stack.pop();
                }
            }
        }
        StringBuilder res = new StringBuilder();
        while (!stack.isEmpty()) {
            res.append(stack.pop());
        }

        System.out.println(res.reverse());
    }

    public static void main(String[] args) throws Exception
    {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    }

    private static boolean eof()
    {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }

    private static byte[] inbuf = new byte[1024];
    static int lenbuf = 0, ptrbuf = 0;

    private static int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }

    private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }

    private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

    private static double nd() { return Double.parseDouble(ns()); }
    private static char nc() { return (char)skip(); }

    private static String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private static char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private static char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }

    private static int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }

    private static int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
}

