Problem: Mad scientist Mike has just finished constructing a new device to search for extraterrestrial intelligence! He was in such a hurry to launch it for the first time that he plugged in the power wires without giving it a proper glance and started experimenting right away. After a while Mike observed that the wires ended up entangled and now have to be untangled again.

The device is powered by two wires "plus" and "minus". The wires run along the floor from the wall (on the left) to the device (on the right). Both the wall and the device have two contacts in them on the same level, into which the wires are plugged in some order. The wires are considered entangled if there are one or more places where one wire runs above the other one. For example, the picture below has four such places (top view):

<image>

Mike knows the sequence in which the wires run above each other. Mike also noticed that on the left side, the "plus" wire is always plugged into the top contact (as seen on the picture). He would like to untangle the wires without unplugging them and without moving the device. Determine if it is possible to do that. A wire can be freely moved and stretched on the floor, but cannot be cut.

To understand the problem better please read the notes to the test samples.

Input

The single line of the input contains a sequence of characters "+" and "-" of length n (1 ≤ n ≤ 100000). The i-th (1 ≤ i ≤ n) position of the sequence contains the character "+", if on the i-th step from the wall the "plus" wire runs above the "minus" wire, and the character "-" otherwise.

Output

Print either "Yes" (without the quotes) if the wires can be untangled or "No" (without the quotes) if the wires cannot be untangled.

Examples

Input

-++-


Output

Yes


Input

+-


Output

No


Input

++


Output

Yes


Input

-


Output

No

Note

The first testcase corresponds to the picture in the statement. To untangle the wires, one can first move the "plus" wire lower, thus eliminating the two crosses in the middle, and then draw it under the "minus" wire, eliminating also the remaining two crosses.

In the second testcase the "plus" wire makes one full revolution around the "minus" wire. Thus the wires cannot be untangled: 

<image>

In the third testcase the "plus" wire simply runs above the "minus" wire twice in sequence. The wires can be untangled by lifting "plus" and moving it higher: 

<image>

In the fourth testcase the "minus" wire runs above the "plus" wire once. The wires cannot be untangled without moving the device itself: 

<image>

Solution (in JAVA):

Solution:
import java.util.*;
import java.io.*;
//import java.lang.*;

public class ranjan{

    public static Read cin;
    //public static InputReader cin;
    public static PrintWriter cout;
    public static boolean[][] visited;
    public static boolean[][] visited2;
    public static final long b = (long)1e9+7;
    public static int fileread = 0; 
    
    public static void main(String ...arg) throws IOException
    {
        /*console writer*/
        cout = new PrintWriter(new BufferedOutputStream(System.out));
        /*Debug Reader*/
        //Scan cin =new Scan();
        if(fileread == 1)
        {
            try
            {
            cin = new Read(new FileInputStream(new File("in3.txt")));
            //cin = new InputReader(new FileInputStream(new File("in2.txt")));
            }
            catch (IOException error){}
        }
        else{
            cin = new Read(System.in);
            //cin = new InputReader(System.in);
        }

        String s = cin.nextLine();
        Stack<Character> stack = new Stack<>();
        for(char ch:s.toCharArray())
        {
            if(stack.isEmpty() || stack.peek() != ch)
                stack.push(ch);
            else
                stack.pop();
        }
        cout.print((stack.isEmpty()? "YES" : "NO" ));
        cout.close();
    }


    public static <K, V> V getOrDefault(HashMap<K,V> map, K key, V defaultValue) {
        return map.containsKey(key) ? map.get(key) : defaultValue;
    }
    

    public static long mod_pow(long x,long n,long mod) {
		long res=1;
		while(n>0) {
			if((n&1)==1)res=res*x%mod;
			x=x*x%mod;
			n>>=1;
		}
		return res;
    }
    public static int gcd(int n1, int n2) 
	{
		int r;
		while (n2 != 0) 
		{
			r = n1 % n2;
			n1 = n2;
			n2 = r;
		}
		return n1;
	}
 
	/*public static int lcm(int n1, int n2) 
	{
		int answer = (n1 * n2) / (gcd(n1, n2));
		return answer;
	}*/


    static class InputReader {
        final InputStream is;
        final byte[] buf = new byte[1024];
        int pos;
        int size;
 
        public InputReader(InputStream is) {
            this.is = is;
        }
 
        public int nextInt() {
            int c = read();
            while (isWhitespace(c))
                c = read();
            int sign = 1;
            if (c == '-') {
                sign = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res = res * 10 + c - '0';
                c = read();
            } while (!isWhitespace(c));
            return res * sign;
        }
 
        int read() {
            if (size == -1)
                throw new InputMismatchException();
            if (pos >= size) {
                pos = 0;
                try {
                    size = is.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (size <= 0)
                    return -1;
            }
            return buf[pos++] & 255;
        }
 
        static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
 
    }

static class RecursionLimiter {
    public static long maxLevel = 1549;

    public static void emerge() {
        if (maxLevel == 0)
            return;
        try {
            throw new IllegalStateException("Too deep, emerging");
        } catch (IllegalStateException e) {
            if (e.getStackTrace().length > maxLevel + 1)
                throw e;
        }
    }
}


static class Scan {
        private byte[] buf=new byte[1024];
        private int index;
        private InputStream in;
        private int total;
        public Scan()
        {
            in=System.in;
        }
        public int scan()throws IOException
        {
            if(total<0)
            throw new InputMismatchException();
            if(index>=total)
            {
                index=0;
                total=in.read(buf);
                if(total<=0)
                return -1;
            }
            return buf[index++];
        }
        public int scanInt()throws IOException
        {
            int integer=0;
            int n=scan();
            while(isWhiteSpace(n))
            n=scan();
            int neg=1;
            if(n=='-')
            {
                neg=-1;
                n=scan();
            }
            while(!isWhiteSpace(n))
            {
                if(n>='0'&&n<='9')
                {
                    integer*=10;
                    integer+=n-'0';
                    n=scan();
                }
                else throw new InputMismatchException();
            }
            return neg*integer;
        }
        public double scanDouble()throws IOException
        {
            double doub=0;
            int n=scan();
            while(isWhiteSpace(n))
            n=scan();
            int neg=1;
            if(n=='-')
            {
                neg=-1;
                n=scan();
            }
            while(!isWhiteSpace(n)&&n!='.')
            {
                if(n>='0'&&n<='9')
                {
                    doub*=10;
                    doub+=n-'0';
                    n=scan();
                }
                else throw new InputMismatchException();
            }
            if(n=='.')
            {
                n=scan();
                double temp=1;
                while(!isWhiteSpace(n))
                {
                    if(n>='0'&&n<='9')
                    {
                        temp/=10;
                        doub+=(n-'0')*temp;
                        n=scan();
                    }
                    else throw new InputMismatchException();
                }
            }
            return doub*neg;
        }
        public String scanString()throws IOException
        {
            StringBuilder sb=new StringBuilder();
            int n=scan();
            while(isWhiteSpace(n))
            n=scan();
            while(!isWhiteSpace(n))
            {
                sb.append((char)n);
                n=scan();
            }
            return sb.toString();
        }
        private boolean isWhiteSpace(int n)
        {
            if(n==' '||n=='\n'||n=='\r'||n=='\t'||n==-1)
            return true;
            return false;
        }
    }

}

class Read
{
    private BufferedReader br;
    private StringTokenizer st;

    public Read(InputStream is)
    { br = new BufferedReader(new InputStreamReader(is)); }

    String next()
    {
        while (st == null || !st.hasMoreElements())
        {
            try {st = new StringTokenizer(br.readLine());}
            catch(IOException e)
                {e.printStackTrace();}
        }
        return st.nextToken();
    }

    int nextInt()
    { return Integer.parseInt(next()); }

    long nextLong()
    { return Long.parseLong(next()); }

    double nextDouble()
    { return Double.parseDouble(next()); }

    String nextLine()
    {
        String str = "";
        try {str = br.readLine();}
        catch(IOException e)
            {e.printStackTrace();}
        return str;
    }
}