import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int A = sc.nextInt();
    int B = sc.nextInt();
    String s = sc.next();
    boolean result = true;
    
    if (s.length()!=A+B+1) result = false;
    else if (s.charAt(A) != '-') result = false;
    else {
      String part1 = s.subString(0, A);
      String part2 = s.subString(A+1);
      if (!checkValid(part1) || !checkValid(part2)) result = false;
    }
	
    if (result) System.out.println("Yes");
	else System.out.println("No");
  }
  
  private boolean checkValid(String s) {
    for (int i=0; i<s.length(); i++) {
      char c = s.charAt(i);
      if (c < '0' || c > '9') {
        return false;
      }
    }
    return true;
  }
}