import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int A = scanner.nextInt();
    int B = scanner.nextInt();
    char[] S = scanner.next().toCharArray();
    if (valid(S, A, B)) System.out.println("Yes");
    else System.out.println("No");
  }
  
  private static boolean valid(char[] S, int A, int B) {
    if (S.length != A + B + 1) return false;
    for (int i = 0; i < A; i++) {
      if (S[i] < '0' || S[i] > '9') return false;
    }
    if (S[A] != '-') return false;
    for (int i = A + 1; i < A + B + 1; i++) {
      if (S[i] < '0' || S[i] > '9') return false;
    }
    return true;
  }
}

/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