-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.*;

import static java.lang.Integer.compare;
import static java.lang.Math.*;
import static java.lang.System.in;
import static java.lang.System.out;
import static java.util.Arrays.deepToString;

/*
 *
 *9/5/18
 *3:14 PM
 *remedy441
 *
 */
public class CF980 {
    public static int mod = (int) (1e9 + 7);
    public static InputReader in;
    public static PrintWriter out;


    public static void solve() throws FileNotFoundException {

    	in = new InputReader(System.in);
    	out = new PrintWriter(System.out);
    	String s = in.nextLine();
    	int cp =0;
    	int cl =0;
    	int l = s.length();
    	for(int i=0;i<l;i++){
    	    if(s.charAt(i)=='-')
    	        cl++;
    	    else cp++;
        }
        if(cp>0&&cl%cp==0)
            out.println("YES");
    	else out.println("NO");


    	out.close();
    }
    public static void main(String[] args) {
    	new Thread(null, new Runnable() {
    		public void run() {
    			try {
    				solve();
    			} catch (Exception e) {
    				e.printStackTrace();
    			}
    		}
    	}, "1", 1 << 26).start();
    }

    static class Pair implements Comparable<Pair> {

    	int x, y, i;

    	Pair(int x, int y, int i) {
    		this.x = x;
    		this.y = y;
    		this.i = i;
    	}

    	Pair(int x, int y) {
    		this.x = x;
    		this.y = y;
    	}

    	public int compareTo(Pair o) {
    		if (this.x != o.x)
    			return compare(this.x, o.x);
    		else
    			return compare(this.y, o.y);
    		//return 0;
    	}

    	public boolean equals(Object o) {
    		if (o instanceof Pair) {
    			Pair p = (Pair) o;
    			return p.x == x && p.y == y && p.i == i;
    		}
    		return false;
    	}

    	public int hashCode() {
    		return new Integer(x).hashCode() * 31 + new Integer(y).hashCode() + new Integer(i).hashCode() * 37;
    	}

    }

    public static long add(long a, long b) {
    	long x = (a + b);
    	while (x >= mod)
    		x -= mod;
    	return x;
    }

    public static long sub(long a, long b) {
    	long x = (a - b);
    	while (x < 0)
    		x += mod;
    	return x;
    }

    public static long mul(long a, long b) {
    	long x = (a * b);
    	while (x >= mod)
    		x -= mod;
    	return x;
    }

    public static boolean isPal(String s) {
    	for (int i = 0, j = s.length() - 1; i <= j; i++, j--) {
    		if (s.charAt(i) != s.charAt(j))
    			return false;
    	}
    	return true;
    }

    public static String rev(String s) {
    	StringBuilder sb = new StringBuilder(s);
    	sb.reverse();
    	return sb.toString();
    }

    public static long gcd(long x, long y) {
    	if (x % y == 0)
    		return y;
    	else
    		return gcd(y, x % y);
    }

    public static int gcd(int x, int y) {
    	if (x % y == 0)
    		return y;
    	else
    		return gcd(y, x % y);
    }

    static int modInverse(int a, int m) {
    	int m0 = m, t, q;
    	int x0 = 0, x1 = 1;
    	if (m == 1)
    		return 0;
    	while (a > 1) {
    		// q is quotient
    		q = a / m;
    		t = m;
    		// m is remainder now, process same as
    		// Euclid's algo
    		m = a % m;
    		a = t;
    		t = x0;
    		x0 = x1 - q * x0;
    		x1 = t;
    	}
    	// Make x1 positive
    	if (x1 < 0)
    		x1 += m0;
    	return x1;
    }

    public static long gcdExtended(long a, long b, long[] x) {

    	if (a == 0) {
    		x[0] = 0;
    		x[1] = 1;
    		return b;
    	}
    	long[] y = new long[2];
    	long gcd = gcdExtended(b % a, a, y);

    	x[0] = y[1] - (b / a) * y[0];
    	x[1] = y[0];

    	return gcd;
    }

    public static long mulmod(long a, long b, long m) {
    	if (m <= 1000000009)
    		return a * b % m;

    	long res = 0;
    	while (a > 0) {
    		if ((a & 1) != 0) {
    			res += b;
    			if (res >= m)
    				res -= m;
    		}
    		a >>= 1;
    		b <<= 1;
    		if (b >= m)
    			b -= m;
    	}
    	return res;
    }

    public static int abs(int a, int b) {
    	return (int) Math.abs(a - b);
    }

    public static long abs(long a, long b) {
    	return (long) Math.abs(a - b);
    }

    public static int max(int a, int b) {
    	if (a > b)
    		return a;
    	else
    		return b;
    }

    public static int min(int a, int b) {
    	if (a > b)
    		return b;
    	else
    		return a;
    }

    public static long max(long a, long b) {
    	if (a > b)
    		return a;
    	else
    		return b;
    }

    public static long min(long a, long b) {
    	if (a > b)
    		return b;
    	else
    		return a;
    }

    public static long pow(long n, long p, long m) {
    	long result = 1;
    	if (p == 0)
    		return 1;
    	if (p == 1)
    		return n;
    	while (p != 0) {
    		if (p % 2 == 1)
    			result *= n;
    		if (result >= m)
    			result %= m;
    		p >>= 1;
    		n *= n;
    		if (n >= m)
    			n %= m;
    	}
    	return result;
    }

    public static long pow(long n, long p) {
    	long result = 1;
    	if (p == 0)
    		return 1;
    	if (p == 1)
    		return n;
    	while (p != 0) {
    		if (p % 2 == 1)
    			result *= n;
    		p >>= 1;
    		n *= n;
    	}
    	return result;
    }

    public static void debug(Object... o) {
    	System.out.println(deepToString(o));
    }

    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 ni() {
    		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 nl() {
    		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[] nIArr(int n) {
    		int a[] = new int[n];
    		for (int i = 0; i < n; i++) {
    			a[i] = ni();
    		}
    		return a;
    	}

    	public long[] nLArr(int n) {
    		long a[] = new long[n];
    		for (int i = 0; i < n; i++) {
    			a[i] = nl();
    		}
    		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);
    	}

    }

}
