import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.OutputStream;
import java.io.InputStreamReader;
import java.io.FileNotFoundException;
import java.io.File;
import java.util.StringTokenizer;
import java.io.Writer;
import java.io.BufferedReader;
import java.io.UnsupportedEncodingException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author MaxHeap
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, FastReader in, OutputWriter out) {
            int a = in.nextInt();
            int b = in.nextInt();
            String[] s = in.next().split("-");
            if (s.length != 2) {
                out.println("No");
                return;
            }
            if (s[0].length() != a || s[1].length() != b) {
                out.println("No");
            } else {
                out.println("Yes");
            }
        }

    }

    static class FastReader {
        BufferedReader reader;
        StringTokenizer st;

        public FastReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream));
            st = null;
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    String line = reader.readLine();
                    if (line == null) {
                        return null;
                    }
                    st = new StringTokenizer(line);
                } catch (Exception e) {
                    throw new RuntimeException();
                }
            }
            return st.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

    }

    static class OutputWriter extends PrintWriter {
        public OutputWriter(OutputStream os, boolean autoFlush) {
            super(os, autoFlush);
        }

        public OutputWriter(Writer out) {
            super(out);
        }

        public OutputWriter(Writer out, boolean autoFlush) {
            super(out, autoFlush);
        }

        public OutputWriter(String fileName) throws FileNotFoundException {
            super(fileName);
        }

        public OutputWriter(String fileName, String csn) throws FileNotFoundException, UnsupportedEncodingException {
            super(fileName, csn);
        }

        public OutputWriter(File file) throws FileNotFoundException {
            super(file);
        }

        public OutputWriter(File file, String csn) throws FileNotFoundException, UnsupportedEncodingException {
            super(file, csn);
        }

        public OutputWriter(OutputStream out) {
            super(out);
        }


        public void flush() {
            super.flush();
        }


        public void close() {
            super.close();
        }

    }
}



Measured memory_bytes: 21588