import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.NoSuchElementException;
import java.util.PriorityQueue;

public class Main {

	void solve() {

		a = in.nextInt();
		b = in.nextInt();
		String s = in.next();

		boolean f = true;

		char[] ss = s.toCharArray();
		if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		}

		out.println(yesno(f));
	}

	// only call
	public static void main(String[] args) {
		new Main().solve();
		out.flush();
	}

	// predefined
	FastScanner in = new FastScanner(System.in);
	static PrintWriter out = new PrintWriter(System.out);

	int n, m, a, b, c, d, e, f;
	int ret;
	ArrayList<Integer> list = new ArrayList<>();
	ArrayDeque<Integer> q = new ArrayDeque<>();

	// 2D-map
	int H, W;
	final int[] dw = new int[] { 0, 1, 0, -1, 1, 1, -1, -1 };
	final int[] dh = new int[] { 1, 0, -1, 0, 1, -1, 1, -1 };

	boolean inField(int nw, int nh) {
		if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		}
		return true;
	}

	// Yes/No
	static String yesno(boolean f) {
		return yesno(f, "Yes", "No");
	}

	static String yesno(boolean f, String yes, String no) {
		return (f ? yes : no);
	}

	// search
	PriorityQueue<Node> pq = new PriorityQueue<>();

	class Node implements Comparable<Node> {

		double score;

		@Override
		public int compareTo(Node o) {
			return Double.compare(this.score, o.score);
		}
	}

	// library
	class FastScanner {
		private final InputStream in;
		private final byte[] buffer = new byte[1024];
		private int ptr = 0;
		private int buflen = 0;

		FastScanner(InputStream in) {
			this.in = in;
		}

		private boolean hasNextByte() {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		}

		private int readByte() {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		}

		private boolean isPrintableChar(int c) {
			return 33 <= c && c <= 126;
		}

		public boolean hasNext() {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		}

		public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		}

		public int nextInt() {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		}

		public double nextDouble() {
			return Double.parseDouble(next());
		}
	}
} import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.ArrayDeque; ArrayDeque java.util import java.util.ArrayList; ArrayList java.util import java.util.NoSuchElementException; NoSuchElementException java.util import java.util.PriorityQueue; PriorityQueue java.util public class Main {

	void solve() {

		a = in.nextInt();
		b = in.nextInt();
		String s = in.next();

		boolean f = true;

		char[] ss = s.toCharArray();
		if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		}

		out.println(yesno(f));
	}

	// only call
	public static void main(String[] args) {
		new Main().solve();
		out.flush();
	}

	// predefined
	FastScanner in = new FastScanner(System.in);
	static PrintWriter out = new PrintWriter(System.out);

	int n, m, a, b, c, d, e, f;
	int ret;
	ArrayList<Integer> list = new ArrayList<>();
	ArrayDeque<Integer> q = new ArrayDeque<>();

	// 2D-map
	int H, W;
	final int[] dw = new int[] { 0, 1, 0, -1, 1, 1, -1, -1 };
	final int[] dh = new int[] { 1, 0, -1, 0, 1, -1, 1, -1 };

	boolean inField(int nw, int nh) {
		if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		}
		return true;
	}

	// Yes/No
	static String yesno(boolean f) {
		return yesno(f, "Yes", "No");
	}

	static String yesno(boolean f, String yes, String no) {
		return (f ? yes : no);
	}

	// search
	PriorityQueue<Node> pq = new PriorityQueue<>();

	class Node implements Comparable<Node> {

		double score;

		@Override
		public int compareTo(Node o) {
			return Double.compare(this.score, o.score);
		}
	}

	// library
	class FastScanner {
		private final InputStream in;
		private final byte[] buffer = new byte[1024];
		private int ptr = 0;
		private int buflen = 0;

		FastScanner(InputStream in) {
			this.in = in;
		}

		private boolean hasNextByte() {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		}

		private int readByte() {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		}

		private boolean isPrintableChar(int c) {
			return 33 <= c && c <= 126;
		}

		public boolean hasNext() {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		}

		public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		}

		public int nextInt() {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		}

		public double nextDouble() {
			return Double.parseDouble(next());
		}
	}
} Main // predefined
	FastScanner in = new FastScanner(System.in); in new FastScanner(System.in) static PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) int n n m m a a b b c c d d e e f; f int ret; ret ArrayList<Integer> list = new ArrayList<>(); list new ArrayList<>() ArrayDeque<Integer> q = new ArrayDeque<>(); q new ArrayDeque<>() // 2D-map
	int H H W; W final int[] dw = new int[] { 0, 1, 0, -1, 1, 1, -1, -1 }; dw new int[] { 0, 1, 0, -1, 1, 1, -1, -1 } final int[] dh = new int[] { 1, 0, -1, 0, 1, -1, 1, -1 }; dh new int[] { 1, 0, -1, 0, 1, -1, 1, -1 } // search
	PriorityQueue<Node> pq = new PriorityQueue<>(); pq new PriorityQueue<>() void solve() {

		a = in.nextInt();
		b = in.nextInt();
		String s = in.next();

		boolean f = true;

		char[] ss = s.toCharArray();
		if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		}

		out.println(yesno(f));
	} solve {

		a = in.nextInt();
		b = in.nextInt();
		String s = in.next();

		boolean f = true;

		char[] ss = s.toCharArray();
		if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		}

		out.println(yesno(f));
	} a = in.nextInt() a in.nextInt() in.nextInt in b = in.nextInt() b in.nextInt() in.nextInt in String s = in.next(); s in.next() in.next in boolean f = true; f true char[] ss = s.toCharArray(); ss s.toCharArray() s.toCharArray s if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		} ss[a] != '-' ss[a] ss a '-' {
			f = false;
		} f = false f false {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		} for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			} int i = 0; int i = 0; i 0 i < a + b + 1 i a + b + 1 a + b + 1 a b 1 i++ i++ i {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			} {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			} if (i == a) {
					continue;
				} i == a i a {
					continue;
				} continue; if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				} !Character.isDigit(ss[i]) Character.isDigit(ss[i]) Character.isDigit Character ss[i] ss i {
					f = false;
					break;
				} f = false f false break; out.println(yesno(f)) out.println out yesno(f) yesno f // only call
	public static void main(String[] args) {
		new Main().solve();
		out.flush();
	} main {
		new Main().solve();
		out.flush();
	} new Main().solve() new Main().solve new Main() out.flush() out.flush out String[] args args boolean inField(int nw, int nh) {
		if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		}
		return true;
	} inField {
		if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		}
		return true;
	} if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		} nw < 0 || nw >= W || nh < 0 || nh >= H nh < 0 nw < 0 || nw >= W || nh < 0 || nh >= H nw < 0 nw 0 nw >= W nw W nh < 0 nh 0 nh >= H nh H {
			return false;
		} return false; false return true; true int nw nw int nh nh // Yes/No
	static String yesno(boolean f) {
		return yesno(f, "Yes", "No");
	} yesno {
		return yesno(f, "Yes", "No");
	} return yesno(f, "Yes", "No"); yesno(f, "Yes", "No") yesno f "Yes" "No" boolean f f static String yesno(boolean f, String yes, String no) {
		return (f ? yes : no);
	} yesno {
		return (f ? yes : no);
	} return (f ? yes : no); (f ? yes : no) f yes no boolean f f String yes yes String no no class Node implements Comparable<Node> {

		double score;

		@Override
		public int compareTo(Node o) {
			return Double.compare(this.score, o.score);
		}
	} Node double score; score @Override
		public int compareTo(Node o) {
			return Double.compare(this.score, o.score);
		} compareTo {
			return Double.compare(this.score, o.score);
		} return Double.compare(this.score, o.score); Double.compare(this.score, o.score) Double.compare Double this.score this this.score o.score o o.score Node o o Comparable class FastScanner {
		private final InputStream in;
		private final byte[] buffer = new byte[1024];
		private int ptr = 0;
		private int buflen = 0;

		FastScanner(InputStream in) {
			this.in = in;
		}

		private boolean hasNextByte() {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		}

		private int readByte() {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		}

		private boolean isPrintableChar(int c) {
			return 33 <= c && c <= 126;
		}

		public boolean hasNext() {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		}

		public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		}

		public int nextInt() {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		}

		public double nextDouble() {
			return Double.parseDouble(next());
		}
	} FastScanner private final InputStream in; in private final byte[] buffer = new byte[1024]; buffer new byte[1024] 1024 private int ptr = 0; ptr 0 private int buflen = 0; buflen 0 FastScanner(InputStream in) {
			this.in = in;
		} FastScanner {
			this.in = in;
		} this.in = in this.in this this.in in InputStream in in private boolean hasNextByte() {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		} hasNextByte {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		} if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			} ptr < buflen ptr buflen {
				return true;
			} return true; true {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			} ptr = 0 ptr 0 try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				} catch (IOException e) {
					e.printStackTrace();
				} IOException e {
					e.printStackTrace();
				} e.printStackTrace() e.printStackTrace e {
					buflen = in.read(buffer);
				} buflen = in.read(buffer) buflen in.read(buffer) in.read in buffer if (buflen <= 0) {
					return false;
				} buflen <= 0 buflen 0 {
					return false;
				} return false; false return true; true private int readByte() {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		} readByte {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		} if (hasNextByte())
				return buffer[ptr++];
			else
				return -1; hasNextByte() hasNextByte return buffer[ptr++]; buffer[ptr++] buffer ptr++ ptr return -1; -1 1 private boolean isPrintableChar(int c) {
			return 33 <= c && c <= 126;
		} isPrintableChar {
			return 33 <= c && c <= 126;
		} return 33 <= c && c <= 126; 33 <= c && c <= 126 33 <= c 33 c c <= 126 c 126 int c c public boolean hasNext() {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		} hasNext {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		} while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++; hasNextByte() && !isPrintableChar(buffer[ptr]) hasNextByte() hasNextByte !isPrintableChar(buffer[ptr]) isPrintableChar(buffer[ptr]) isPrintableChar buffer[ptr] buffer ptr ptr++ ptr return hasNextByte(); hasNextByte() hasNextByte public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		} next {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		} if (!hasNext())
				throw new NoSuchElementException(); !hasNext() hasNext() hasNext throw new NoSuchElementException(); new NoSuchElementException() StringBuilder sb = new StringBuilder(); sb new StringBuilder() int b = readByte(); b readByte() readByte while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			} isPrintableChar(b) isPrintableChar b {
				sb.appendCodePoint(b);
				b = readByte();
			} sb.appendCodePoint(b) sb.appendCodePoint sb b b = readByte() b readByte() readByte return sb.toString(); sb.toString() sb.toString sb public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		} nextLong {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		} if (!hasNext())
				throw new NoSuchElementException(); !hasNext() hasNext() hasNext throw new NoSuchElementException(); new NoSuchElementException() long n = 0; n 0 boolean minus = false; minus false int b = readByte(); b readByte() readByte if (b == '-') {
				minus = true;
				b = readByte();
			} b == '-' b '-' {
				minus = true;
				b = readByte();
			} minus = true minus true b = readByte() b readByte() readByte if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			} b < '0' || '9' < b b < '0' b '0' '9' < b '9' b {
				throw new NumberFormatException();
			} throw new NumberFormatException(); new NumberFormatException() while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			} true {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			} if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				} '0' <= b && b <= '9' '0' <= b '0' b b <= '9' b '9' {
					n *= 10;
					n += b - '0';
				} n *= 10 n 10 n += b - '0' n b - '0' b '0' if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				} b == -1 || !isPrintableChar(b) b == -1 b -1 1 !isPrintableChar(b) isPrintableChar(b) isPrintableChar b {
					return minus ? -n : n;
				} return minus ? -n : n; minus ? -n : n minus -n n n {
					throw new NumberFormatException();
				} throw new NumberFormatException(); new NumberFormatException() b = readByte() b readByte() readByte public int nextInt() {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		} nextInt {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		} long nl = nextLong(); nl nextLong() nextLong if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException(); nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE nl < Integer.MIN_VALUE nl Integer.MIN_VALUE Integer Integer.MIN_VALUE nl > Integer.MAX_VALUE nl Integer.MAX_VALUE Integer Integer.MAX_VALUE throw new NumberFormatException(); new NumberFormatException() return (int) nl; (int) nl public double nextDouble() {
			return Double.parseDouble(next());
		} nextDouble {
			return Double.parseDouble(next());
		} return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next public class Main {

	void solve() {

		a = in.nextInt();
		b = in.nextInt();
		String s = in.next();

		boolean f = true;

		char[] ss = s.toCharArray();
		if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		}

		out.println(yesno(f));
	}

	// only call
	public static void main(String[] args) {
		new Main().solve();
		out.flush();
	}

	// predefined
	FastScanner in = new FastScanner(System.in);
	static PrintWriter out = new PrintWriter(System.out);

	int n, m, a, b, c, d, e, f;
	int ret;
	ArrayList<Integer> list = new ArrayList<>();
	ArrayDeque<Integer> q = new ArrayDeque<>();

	// 2D-map
	int H, W;
	final int[] dw = new int[] { 0, 1, 0, -1, 1, 1, -1, -1 };
	final int[] dh = new int[] { 1, 0, -1, 0, 1, -1, 1, -1 };

	boolean inField(int nw, int nh) {
		if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		}
		return true;
	}

	// Yes/No
	static String yesno(boolean f) {
		return yesno(f, "Yes", "No");
	}

	static String yesno(boolean f, String yes, String no) {
		return (f ? yes : no);
	}

	// search
	PriorityQueue<Node> pq = new PriorityQueue<>();

	class Node implements Comparable<Node> {

		double score;

		@Override
		public int compareTo(Node o) {
			return Double.compare(this.score, o.score);
		}
	}

	// library
	class FastScanner {
		private final InputStream in;
		private final byte[] buffer = new byte[1024];
		private int ptr = 0;
		private int buflen = 0;

		FastScanner(InputStream in) {
			this.in = in;
		}

		private boolean hasNextByte() {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		}

		private int readByte() {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		}

		private boolean isPrintableChar(int c) {
			return 33 <= c && c <= 126;
		}

		public boolean hasNext() {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		}

		public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		}

		public int nextInt() {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		}

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

	void solve() {

		a = in.nextInt();
		b = in.nextInt();
		String s = in.next();

		boolean f = true;

		char[] ss = s.toCharArray();
		if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		}

		out.println(yesno(f));
	}

	// only call
	public static void main(String[] args) {
		new Main().solve();
		out.flush();
	}

	// predefined
	FastScanner in = new FastScanner(System.in);
	static PrintWriter out = new PrintWriter(System.out);

	int n, m, a, b, c, d, e, f;
	int ret;
	ArrayList<Integer> list = new ArrayList<>();
	ArrayDeque<Integer> q = new ArrayDeque<>();

	// 2D-map
	int H, W;
	final int[] dw = new int[] { 0, 1, 0, -1, 1, 1, -1, -1 };
	final int[] dh = new int[] { 1, 0, -1, 0, 1, -1, 1, -1 };

	boolean inField(int nw, int nh) {
		if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		}
		return true;
	}

	// Yes/No
	static String yesno(boolean f) {
		return yesno(f, "Yes", "No");
	}

	static String yesno(boolean f, String yes, String no) {
		return (f ? yes : no);
	}

	// search
	PriorityQueue<Node> pq = new PriorityQueue<>();

	class Node implements Comparable<Node> {

		double score;

		@Override
		public int compareTo(Node o) {
			return Double.compare(this.score, o.score);
		}
	}

	// library
	class FastScanner {
		private final InputStream in;
		private final byte[] buffer = new byte[1024];
		private int ptr = 0;
		private int buflen = 0;

		FastScanner(InputStream in) {
			this.in = in;
		}

		private boolean hasNextByte() {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		}

		private int readByte() {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		}

		private boolean isPrintableChar(int c) {
			return 33 <= c && c <= 126;
		}

		public boolean hasNext() {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		}

		public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		}

		public int nextInt() {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		}

		public double nextDouble() {
			return Double.parseDouble(next());
		}
	}
} Main
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.NoSuchElementException;
import java.util.PriorityQueue;

public class Main {

	void solve() {

		a = in.nextInt();
		b = in.nextInt();
		String s = in.next();

		boolean f = true;

		char[] ss = s.toCharArray();
		if (ss[a] != '-') {
			f = false;
		} else {
			for (int i = 0; i < a + b + 1; i++) {
				if (i == a) {
					continue;
				}
				if (!Character.isDigit(ss[i])) {
					f = false;
					break;
				}
			}
		}

		out.println(yesno(f));
	}

	// only call
	public static void main(String[] args) {
		new Main().solve();
		out.flush();
	}

	// predefined
	FastScanner in = new FastScanner(System.in);
	static PrintWriter out = new PrintWriter(System.out);

	int n, m, a, b, c, d, e, f;
	int ret;
	ArrayList<Integer> list = new ArrayList<>();
	ArrayDeque<Integer> q = new ArrayDeque<>();

	// 2D-map
	int H, W;
	final int[] dw = new int[] { 0, 1, 0, -1, 1, 1, -1, -1 };
	final int[] dh = new int[] { 1, 0, -1, 0, 1, -1, 1, -1 };

	boolean inField(int nw, int nh) {
		if (nw < 0 || nw >= W || nh < 0 || nh >= H) {
			return false;
		}
		return true;
	}

	// Yes/No
	static String yesno(boolean f) {
		return yesno(f, "Yes", "No");
	}

	static String yesno(boolean f, String yes, String no) {
		return (f ? yes : no);
	}

	// search
	PriorityQueue<Node> pq = new PriorityQueue<>();

	class Node implements Comparable<Node> {

		double score;

		@Override
		public int compareTo(Node o) {
			return Double.compare(this.score, o.score);
		}
	}

	// library
	class FastScanner {
		private final InputStream in;
		private final byte[] buffer = new byte[1024];
		private int ptr = 0;
		private int buflen = 0;

		FastScanner(InputStream in) {
			this.in = in;
		}

		private boolean hasNextByte() {
			if (ptr < buflen) {
				return true;
			} else {
				ptr = 0;
				try {
					buflen = in.read(buffer);
				} catch (IOException e) {
					e.printStackTrace();
				}
				if (buflen <= 0) {
					return false;
				}
			}
			return true;
		}

		private int readByte() {
			if (hasNextByte())
				return buffer[ptr++];
			else
				return -1;
		}

		private boolean isPrintableChar(int c) {
			return 33 <= c && c <= 126;
		}

		public boolean hasNext() {
			while (hasNextByte() && !isPrintableChar(buffer[ptr]))
				ptr++;
			return hasNextByte();
		}

		public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (isPrintableChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			long n = 0;
			boolean minus = false;
			int b = readByte();
			if (b == '-') {
				minus = true;
				b = readByte();
			}
			if (b < '0' || '9' < b) {
				throw new NumberFormatException();
			}
			while (true) {
				if ('0' <= b && b <= '9') {
					n *= 10;
					n += b - '0';
				} else if (b == -1 || !isPrintableChar(b)) {
					return minus ? -n : n;
				} else {
					throw new NumberFormatException();
				}
				b = readByte();
			}
		}

		public int nextInt() {
			long nl = nextLong();
			if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE)
				throw new NumberFormatException();
			return (int) nl;
		}

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