-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.util.*;


import java.io.*;
import java.lang.*;
import java.lang.reflect.Array;
import java.math.*;

public class Test
{
	static class pair implements Comparable<pair>
	 {
		Integer x,y;
		pair(int x,int y)
		{
			this.x=x;
			this.y=y;
		}
		public int compareTo(pair o)
		{
			if(x<o.x)
				return -1;
			else
				return 1;
		}  
	}
	static int ans=0;
	static long mod=1000000007;
	static boolean prime[];
	
	public static void main(String args[])
	{
		InputReader in=new InputReader(System.in);
		PrintWriter pw=new PrintWriter(System.out);
		String str=in.nextLine();
		int l=0,p=0;
		for(int i=0;i<str.length();i++)
		{
			if(str.charAt(i)=='o')
				p++;
			else
				l++;
		}
		if(l==0 || p==0)
			System.out.println("YES");
		else
		{
			if(l%p==0)
				System.out.println("YES");
			else
				System.out.println("NO");
		}
		pw.flush();
	}
	public static int distance(int x,int y,int p,int q)
	{
		int a=(x-p)*(x-p);
		int b=(y-q)*(y-q);
		int dis=a+b;
		return dis;
	}
	public static int bnum(int num)
	{
		int ans=0;
		for(int i=31;i>=0;i--)
		{
			if((num&(1<<i))!=0)
			{
				ans+=Math.pow(10,i);
			}
		}
		return ans;
	}
	public static int bsdown(int a[],int item)
	{
		int low=0,high=a.length-1,ans=-1;
		while(low<=high)
		{
			int mid=low+(high-low)/2;
			if(a[mid]<=item)
			{
				ans=mid;
				low=mid+1;
			}
			else
				high=mid-1;
				
		}
		return ans;
	}
	public static long inverse(long num)
	{
		return fastpow(num,mod-2,mod);
	}
	public static int bsupper(int a[],int item)
	{
		int low=0,high=a.length-1,ans=-1;
		while(low<=high)
		{
			int mid=low+(high-low)/2;
			if(a[mid]>=item)
			{
				ans=mid;
				high=mid-1;
			}
			else
				low=mid+1;
				
		}
		return ans;
	}	
	public static boolean isprime(int n)
	{
		for(int i=2;i*i<=n;i++)
		{
			if(n%i==0)
				return false;
		}
		return true;
	}
	public static long fact(long a,long mod)
	{
		long ans=1;
		for(int i=1;i<=a;i++)
		{
			ans*=i;
			ans%=mod;
		}
		return ans%mod;
		
	}
	public static long ncr(long n,long r,long mod)
	{
		long nom=1,dom=1;
		nom=(fact(n,mod))%mod;
		dom=(fact(r,mod)*fact(n-r,mod))%mod;
		return (nom*fastpow(dom,mod-2,mod))%mod;
	}
	public static long gcd(long x, long y)
	{
		if(x==0)
			return y;
		if(y==0)
			return x;
		long r=0, a, b;
		a = (x > y) ? x : y; // a is greater number
		b = (x < y) ? x : y; // b is smaller number
		r = b;
		while(a % b != 0)
		{
			r = a % b;
			a = b;
			b = r;
		}
		return r;
	}
	public static void prime(int n)
	{
		prime[0]=true;
		prime[1]=true;
		for(int i=2;i*i<=n;i++)
		{
			if(prime[i])
				continue;
			for(int j=i;j*i<=n;j++)
			{
				prime[i*j]=true;
			}
		}
	}
	static class InputReader 
	{
		 
		private final InputStream stream;
		private final byte[] buf = new byte[8192];
		private int curChar, snumChars;
		private SpaceCharFilter filter;

		public InputReader(InputStream stream) 
		{
			this.stream = stream;
		}

		public int snext() 
		{
			if (snumChars == -1)
				throw new InputMismatchException();
			if (curChar >= snumChars) 
			{
				curChar = 0;
				try 
				{
					snumChars = stream.read(buf);
				}
				catch (IOException e) 
				{
					throw new InputMismatchException();
				}
				if (snumChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}

		public int nextInt()
		{
			int c = snext();
			while (isSpaceChar(c))
			{
				c = snext();
			}
			int sgn = 1;
			if (c == '-')
			{
				sgn = -1;
				c = snext();
			}
			int res = 0;
			do
			{
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			}
			while (!isSpaceChar(c));
			return res * sgn;
		}

		public long nextLong() 
		{
			int c = snext();
			while (isSpaceChar(c)) 
			{
				c = snext();
			}
			int sgn = 1;
			if (c == '-') 
			{
				sgn = -1;
				c = snext();
			}
			long res = 0;
			do
			{
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = snext();
			}
			while (!isSpaceChar(c));
			return res * sgn;
		}

		public int[] nextIntArray(int n) 
		{
			int a[] = new int[n];
			for (int i = 0; i < n; i++) 
			{
				a[i] = nextInt();
			}
			return a;
		}

		public String readString() 
		{
			int c = snext();
			while (isSpaceChar(c)) 
			{
				c = snext();
			}
			StringBuilder res = new StringBuilder();
			do
			{
				res.appendCodePoint(c);
				c = snext();
			}
			while (!isSpaceChar(c));
			return res.toString();
		}

		public String nextLine()
		{
			int c = snext();
			while (isSpaceChar(c))
				c = snext();
			StringBuilder res = new StringBuilder();
			do 
			{
				res.appendCodePoint(c);
				c = snext();
			}
			while (!isEndOfLine(c));
			return res.toString();
		}

		public boolean isSpaceChar(int c) 
		{
			if (filter != null)
				return filter.isSpaceChar(c);
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

		private boolean isEndOfLine(int c) 
		{
			return c == '\n' || c == '\r' || c == -1;
		}

		public interface SpaceCharFilter 
		{
			public boolean isSpaceChar(int ch);
		}
	}
	public static long fastpow(long a,long b,long mod)
	{
		long ans=1;
		while(b!=0)
		{
			if(b%2==1)
			{
				ans=(ans*a)%mod;
			}
			a=(a*a)%mod;
			b/=2;
		}
		return ans;
	}
}