-oo-oo------
 -----------------------------------o---------------------o--------------------------
 --o-o-----o----o--oo-o-----ooo-oo---o--
 ---
 ----------------------o---o----o---o-----------o-o-----o
 -o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o
 ---------------------------------o----------------------------oo------------------------------------
 ----------------------------------------------------------------------o-o---------------------
 -----------------o-o--oo------o--------o---o--o----------------oooo-------------ooo-----ooo-----o
 -o-o--o-o--o-----o-----o-o--o-o---oooo-o
 oo--
 oo-ooo
 oooooooooo-ooo-oooooo-ooooooooooooooo--o-o-oooooooooooooo-oooooooooooooo
 ------------------------o------------o-----o----------------
 -ooo--
 o------ooo--o-o-oo--o------o----ooo-----o-----o-----o-ooo-o---o----oo
 ---o----o
 -------o--------------------o--o---------------o---o--o-----
 o----------o----------o----------o----------o----------o----------o----------o----------o----------o
 ------o-o--o-----o--
 ----------------------------------------------------------------------------------------------------
 o----------------------oo----
 -o-ooo-o--o----o--o-o-oo-----------o-o-
 o--o--o--o--o--o--o--o--o--o--o--o--
 oooooooo----------
 -o--o--------o--o------o---o-o----------o-------o-o-o-------oo----oo------o------oo--o--
 o---o---o---o---o----o----o----o---o---o---o
 -------------o----ooo-----o-o-------------ooo-----------ooo------o----oo---
 -oo
 ------oo----------o------o-----o---------o------------o----o--o
 ------------o------------------o-----------------------o-----------o
 ---------------o-o----
 oo----------------------o--------------o--------------o-----
 o---------o---------o---------o---------o---------o---------o---------o---------o
 oo-o-ooooo---oo---o-oo---o--o-ooo-o---o-oo---oo---oooo---o---o-oo-oo-o-ooo----ooo--oo--o--oo-o-oo
 oooo--
 ----o---o-------------------------
 -o---o-
 ooo-ooooooo-oo-ooooooooo-oooooooooooooo-oooo-o-oooooooooo--oooooooooooo-oooooooooo-ooooooo
 -o--o-oo---o-o-o--o-o----oo------oo-----o----o-o-o--oo-o--o---o--o----------o---o-o-oo---o--o-oo-o--
 --o---oooo--o-o--o-----o----ooooo--o-oo--o------oooo--------------ooo-o-o----
 ---ooo
 ------------------o----------------------------------o-o-------------
 --------o--------o--------o--------o--------o--------o--------o--------o--------
 ---o--
 oo--o--o--------oo----------------o-----------o----o-----o----------o---o---o-----o---------ooo---
 oo--o-o-o----o-oooo-ooooo---o-oo--o-o--ooo--o--oooo--oo----o----o-o-oooo---o-oooo--ooo-o-o----oo---
 ------oo----o----o-oo-o--------o-----oo-----------------------o------------o-o----oo---------
 o---o---------------
 -o-
 -----------------------------o--o-o-------
 ooo---------
 o-ooooo
 -o-o--
 o-------o-------o-------------
 -----o-----oo-o-o-o-o----o---------oo---ooo-------------o----o---o-o
 ------oooo
 -o---
 --o---o----------o----o----------o--o-o-----o-oo---oo--oo---o-------------oo-----o-------------o---o
 ---o
 oo-
 --o--o----o-o---o--o----o-o--oo-----o-oo--o---o---ooo-o--
 ooo-
 o-oo-o--oo----o-o----------o---o--o----o----o---oo-ooo-o--o-
 ooooo-
 o---o----
 o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-
 ----o----o

YES
 YES
 YES
 YES YES
 YES
 NO
 YES
 NO
 NO
 YES
 NO
 NO
 YES
 YES
 YES
 NO
 YES
 YES
 YES
 YES NO
 YES
 YES
 NO
 NO
 YES
 YES
 NO
 YES
 YES
 YES
 YES
 YES
 NO
 NO
 YES
 NO
 NO
 NO
 NO
 YES
 YES
 YES
 YES
 NO
 NO
 NO
 YES
 YES
 YES
 YES
 NO
 YES
 YES
 YES
 NO
 YES
 YES
 YES
 NO
 YES
 NO
 YES
 NO
 NO
 YES
 YES



import java.io.*;
import java.util.*;

/**
 *  
 * @author akashvermaofskt
 * Coding is love <3!
 */

public class A {
    public static void main(String args[]) {
        try {
            String s=next();
            int p=0,l=0;
            for(int i=0;i<s.length();i++){
                if(s.charAt(i)=='-')l++;
                else p++;
            }
            
            if(p==0){
                bw.write("YES\n");
            }else
            if(l%p==0)
                bw.write("YES\n");
            else
                bw.write("NO\n");
            
            bw.flush();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    //TEMPLATE
    
    //******************************************************************************
    // Fast I/O 
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
    static StringTokenizer st = null;
    static int mod=1000000007;

    static String next() {
        while (st == null || !st.hasMoreElements()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }
    
    static int nextInt() {
        return Integer.parseInt(next());
    }
    
    static long nextLong() {
        return Long.parseLong(next());
    }

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

    static int b_search(int l,int r,int A[],int key){
        int ans=0;
        l=0;r=1000000000;

        while(l<r){
            //System.out.println(ans);
            ans=(l+r)/2;
            long temp=0;
            for (int i = 0; i < A.length; i++) {
                temp+=(long)Math.ceil((double)A[i]/(double)ans);
            }

            if(temp<=key){
                r=ans;
            }
            else{
                l=ans+1;
                ans=r;
            }
        }

        return ans;
    }

//******************************************************************************
//Modulo and FastExpo
    static long modInverse(long a)
    {
       return power(a, mod - 2,mod);
    }
     
    // To compute x^y under modulo m
    static long power(long x, long y, int p)
    {
        // Initialize result
        long res = 1;     
        // Update x if it is more  
        // than or equal to p
        x = x % p; 
     while (y > 0)
        {
            // If y is odd, multiply x
            // with result
            if((y & 1)==1)
                res = (res * x) % p;
            // y must be even now
            // y = y / 2
            y = y >> 1; 
            x = (x * x) % p; 
        }
        return res;
    }
//******************************************************************************
//GCD
    static long gcd(long a, long b)
    {
        if (a == 0)
            return b;
         
        return gcd(b%a, a);
    }

    //******************************************************************************
    // Useful user datatype
    
    static class Pair{
        public long x;
        public long y;

        public Pair(long first, long second){
            this.x = first;
            this.y = second;
            }
        @Override
        public String toString() {
        return "(" + x + "," + y + ")";
        }
    }

    static Comparator csort=new Comparator<Pair>(){
                    public int compare(Pair a, Pair b) {
                        if(a.x < b.x)
                        return -1;
                        else if (a.x > b.x)
                        return 1;
                        else if(a.y < b.y)
                        return -1;
                        else if (a.y > b.y)
                        return 1;
                        else
                        return 0;
                    }
                };

    //******************************************************************************
    //N choose K
    public static long choose(long total, long choose){
        if(total < choose)
            return 0;
        if(choose == 0 || choose == total)
            return 1;
        return choose(total-1,choose-1)+choose(total-1,choose);
    }

    //******************************************************************************
    //Permutations
    // simply prints all permutation - to see how it works
    private static void printPermutations( Comparable[] c ) {
            System.out.println( Arrays.toString( c ) );
            while ( ( c = nextPermutation( c ) ) != null ) {
                    System.out.println( Arrays.toString( c ) );
            }
    }

    // modifies c to next permutation or returns null if such permutation does not exist
    private static Comparable[] nextPermutation( final Comparable[] c ) {
            // 1. finds the largest k, that c[k] < c[k+1]
            int first = getFirst( c );
            if ( first == -1 ) return null; // no greater permutation
            // 2. find last index toSwap, that c[k] < c[toSwap]
            int toSwap = c.length - 1;
            while ( c[ first ].compareTo( c[ toSwap ] ) >= 0 )
                    --toSwap;
            // 3. swap elements with indexes first and last
            swap( c, first++, toSwap );
            // 4. reverse sequence from k+1 to n (inclusive) 
            toSwap = c.length - 1;
            while ( first < toSwap )
                    swap( c, first++, toSwap-- );
            return c;
    }

    // finds the largest k, that c[k] < c[k+1]
    // if no such k exists (there is not greater permutation), return -1
    private static int getFirst( final Comparable[] c ) {
            for ( int i = c.length - 2; i >= 0; --i )
                    if ( c[ i ].compareTo( c[ i + 1 ] ) < 0 )
                            return i;
            return -1;
    }

    // swaps two elements (with indexes i and j) in array 
    private static void swap( final Comparable[] c, final int i, final int j ) {
            final Comparable tmp = c[ i ];
            c[ i ] = c[ j ];
            c[ j ] = tmp;
    }
    //******************************************************************************
    // DSU
    //Maintain an Array A with N elements and Array size for size of each set, intialize A[i]=i and size[i]=1

    static int root(int A[],int i){
        while(A[i]!=i){
            A[i]=A[A[i]];
            i=A[i];
        }
        return i;
    }

    static boolean find(int A[],int a,int b){
        if(root(A,a)==root(A,b))return true;
        else return false;
    }

    static void union(int A[],int size[],int a,int b){
        int ra=root(A,a);
        int rb=root(A,b);

        if(ra==rb)return;

        if(size[ra]<size[rb]){
            A[ra]=A[rb];
            size[rb]+=size[ra];
        }else{
            A[rb]=A[ra];
            size[ra]+=size[rb];
        }
    }

    //**************************************************************************
    //BinarySearch
    /* binary search for 5:
                v-- lower bound
         1 2 3 4 5 5 5 6 7 9
                      ^-- upper bound
        
            binary search for 8
                        v-- lower bound
       1 2 3 4 5 5 5 6 7 9
                        ^-- upper bound
    */
    //For finding greater than 
    static int upper_bound(int A[],int key){
        int first = 0;
        int last = A.length;
        int mid;

        while (first < last) {
            mid =first+(last - first)/2; 

            if (A[mid] <= key)  
                first = mid + 1; 
            else 
                last = mid;
        }

        return first;
    }
    
    //For finding greater than equal to
    static int lower_bound(int A[],int key){
        int first = 0;
        int last = A.length;
        int mid=0;
        
        while (first < last) {
            mid = first + ((last - first) >> 1); 
            if (A[mid] < key)  
                first = mid + 1; 
            else 
                last = mid;
        }
        
        return first;
    }
    //**************************************************************************
}
