import java.util.*;

public class Main {
  public static void main(String[] args) throws Exception {
    
    Scanner sc = new Scanner(System.in);
    int A = sc.nextInt();
    int B = sc.nextInt();
    String S = sc.next();
    if (S.length() != A + B + 1){
      System.out.println("No");
    }
    String case1 = S.substring(0, A);
    char case2 = S.charAt(A);
    String case3 = S.substring(A+1);
 
    if (!case1.matches("[0-9]*")) {
      System.out.println("No");
      return;
    }
    if (case2 != '-') {
      System.out.println("No");
      return;
    }
    if (case3.matches("[0-9]*")) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
}
    
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz