-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
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 YES
 YES
 NO
 YES
 NO
 YES
 NO
 NO
 YES
 YES

import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;
import java.io.IOException;import java.io.PrintStream;import java.io.PrintWriter;
import java.security.AccessControlException;import java.util.Arrays;import java.util.Collection;
import java.util.Comparator;import java.util.List;import java.util.Map;import java.util.Objects;
import java.util.Scanner;import java.util.TreeMap;import java.util.function.Function;
import java.util.stream.Collectors;import java.util.stream.IntStream;import java.util.stream.LongStream;
import java.util.stream.Stream;public class _p000980A {static public void main(final String[] args) 
throws IOException{p000980A._main(args);}
static private class p000980A extends Solver{public p000980A(){nameIn="in/900/p000980A.in"
;singleTest=true;}@Override public void solve()throws IOException{String s=sc.nextLine
().trim();int cn=0;int cb=0;for(int i=0;i<s.length();i++){if(s.charAt(i)=='-'){cn
++;}else{cb++;}}pw.println(cb==0 || cn%cb==0?"YES":"NO");}static public void _main
(String[]args)throws IOException{new p000980A().run();}}static private class Pair
<K,V>{private K k;private V v;public Pair(final K t,final V u){this.k=t;this.v=u
;}public K getKey(){return k;}public V getValue(){return v;}}static private abstract class
 Solver{protected String nameIn=null;protected String nameOut=null;protected boolean
 singleTest=false;protected boolean preprocessDebug=false;protected boolean doNotPreprocess
=false;protected PrintStream debugPrintStream=null;protected Scanner sc=null;protected
 PrintWriter pw=null;final static String SPACE=" ";final static String SPACES="\\s+"
;private void process()throws IOException{if(!singleTest){int t=lineToIntArray()
[0];while(t-->0){solve();}}else{solve();}}abstract protected void solve()throws 
IOException;protected int[]lineToIntArray()throws IOException{return Arrays.stream
(sc.nextLine().trim().split(SPACES)).mapToInt(Integer::valueOf).toArray();}protected
 long[]lineToLongArray()throws IOException{return Arrays.stream(sc.nextLine().trim
().split(SPACES)).mapToLong(Long::valueOf).toArray();}protected void run()throws
 IOException{boolean done=false;try{if(nameIn!=null && new File(nameIn).exists()
){try(FileInputStream fis=new FileInputStream(nameIn);PrintWriter pw0=select_output
();){done=true;sc=new Scanner(fis);pw=pw0;process();}}}catch(IOException ex){}catch
(AccessControlException ex){}if(!done){try(PrintWriter pw0=select_output();){sc=
new Scanner(System.in);pw=pw0;process();}}}private PrintWriter select_output()throws
 FileNotFoundException{if(nameOut!=null){return new PrintWriter(nameOut);}return
 new PrintWriter(System.out);}public static Map<Integer,List<Integer>>mapi(final
 int[]a){return IntStream.range(0,a.length).collect(()->new TreeMap<Integer,List
<Integer>>(),(res,i)->{if(!res.containsKey(a[i])){res.put(a[i],Stream.of(i).collect
(Collectors.toList()));}else{res.get(a[i]).add(i);}},Map::putAll);}public static
 Map<Long,List<Integer>>mapi(final long[]a){return IntStream.range(0,a.length).collect
(()->new TreeMap<Long,List<Integer>>(),(res,i)->{if(!res.containsKey(a[i])){res.
put(a[i],Stream.of(i).collect(Collectors.toList()));}else{res.get(a[i]).add(i);}
},Map::putAll);}public static<T>Map<T,List<Integer>>mapi(final T[]a){return IntStream
.range(0,a.length).collect(()->new TreeMap<T,List<Integer>>(),(res,i)->{if(!res.
containsKey(a[i])){res.put(a[i],Stream.of(i).collect(Collectors.toList()));}else
{res.get(a[i]).add(i);}},Map::putAll);}public static<T>Map<T,List<Integer>>mapi(
final T[]a,Comparator<T>cmp){return IntStream.range(0,a.length).collect(()->new 
TreeMap<T,List<Integer>>(cmp),(res,i)->{if(!res.containsKey(a[i])){res.put(a[i],
Stream.of(i).collect(Collectors.toList()));}else{res.get(a[i]).add(i);}},Map::putAll
);}public static Map<Integer,List<Integer>>mapi(final IntStream a){int[]i=new int
[]{0};return a.collect(()->new TreeMap<Integer,List<Integer>>(),(res,v)->{if(!res
.containsKey(v)){res.put(v,Stream.of(i[0]).collect(Collectors.toList()));}else{res
.get(v).add(i[0]);}i[0]++;},Map::putAll);}public static Map<Long,List<Integer>>mapi
(final LongStream a){int[]i=new int[]{0};return a.collect(()->new TreeMap<Long,List
<Integer>>(),(res,v)->{if(!res.containsKey(v)){res.put(v,Stream.of(i[0]).collect
(Collectors.toList()));}else{res.get(v).add(i[0]);}i[0]++;},Map::putAll);}public
 static<T>Map<T,List<Integer>>mapi(final Stream<T>a,Comparator<T>cmp){int[]i=new
 int[]{0};return a.collect(()->new TreeMap<T,List<Integer>>(cmp),(res,v)->{if(!res
.containsKey(v)){res.put(v,Stream.of(i[0]).collect(Collectors.toList()));}else{res
.get(v).add(i[0]);}},Map::putAll);}public static<T>Map<T,List<Integer>>mapi(final
 Stream<T>a){int[]i=new int[]{0};return a.collect(()->new TreeMap<T,List<Integer
>>(),(res,v)->{if(!res.containsKey(v)){res.put(v,Stream.of(i[0]).collect(Collectors
.toList()));}else{res.get(v).add(i[0]);}},Map::putAll);}public static List<int[]
>listi(final int[]a){return IntStream.range(0,a.length).mapToObj(i->new int[]{a[
i],i}).collect(Collectors.toList());}public static List<long[]>listi(final long[
]a){return IntStream.range(0,a.length).mapToObj(i->new long[]{a[i],i}).collect(Collectors
.toList());}public static<T>List<Pair<T,Integer>>listi(final T[]a){return IntStream
.range(0,a.length).mapToObj(i->new Pair<T,Integer>(a[i],i)).collect(Collectors.toList
());}public static List<int[]>listi(final IntStream a){int[]i=new int[]{0};return
 a.mapToObj(v->new int[]{v,i[0]++}).collect(Collectors.toList());}public static 
List<long[]>listi(final LongStream a){int[]i=new int[]{0};return a.mapToObj(v->new
 long[]{v,i[0]++}).collect(Collectors.toList());}public static<T>List<Pair<T,Integer
>>listi(final Stream<T>a){int[]i=new int[]{0};return a.map(v->new Pair<T,Integer
>(v,i[0]++)).collect(Collectors.toList());}public static String join(final int[]
a){return Arrays.stream(a).mapToObj(Integer::toString).collect(Collectors.joining
(SPACE));}public static String join(final long[]a){return Arrays.stream(a).mapToObj
(Long::toString).collect(Collectors.joining(SPACE));}public static<T>String join
(final T[]a){return Arrays.stream(a).map(v->Objects.toString(v)).collect(Collectors
.joining(SPACE));}public static<T>String join(final T[]a,final Function<T,String
>toString){return Arrays.stream(a).map(v->toString.apply(v)).collect(Collectors.
joining(SPACE));}public static<T>String join(final Collection<T>a){return a.stream
().map(v->Objects.toString(v)).collect(Collectors.joining(SPACE));}public static
<T>String join(final Collection<T>a,final Function<T,String>toString){return a.stream
().map(v->toString.apply(v)).collect(Collectors.joining(SPACE));}public static<T
>String join(final Stream<T>a){return a.map(v->Objects.toString(v)).collect(Collectors
.joining(SPACE));}public static<T>String join(final Stream<T>a,final Function<T,
String>toString){return a.map(v->toString.apply(v)).collect(Collectors.joining(SPACE
));}public static<T>String join(final IntStream a){return a.mapToObj(Integer::toString
).collect(Collectors.joining(SPACE));}public static<T>String join(final LongStream
 a){return a.mapToObj(Long::toString).collect(Collectors.joining(SPACE));}public
 static List<Integer>list(final int[]a){return Arrays.stream(a).mapToObj(Integer
::valueOf).collect(Collectors.toList());}public static List<Integer>list(final IntStream
 a){return a.mapToObj(Integer::valueOf).collect(Collectors.toList());}public static
 List<Long>list(final long[]a){return Arrays.stream(a).mapToObj(Long::valueOf).collect
(Collectors.toList());}public static List<Long>list(final LongStream a){return a
.mapToObj(Long::valueOf).collect(Collectors.toList());}public static<T>List<T>list
(final Stream<T>a){return a.collect(Collectors.toList());}public static<T>List<T
>list(final T[]a){return Arrays.stream(a).collect(Collectors.toList());}}}
