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();
    char p[] = s.toCharArray();
    int flag = 0;
    for(int i = 0;i < a;i++){
      if(p[i] < '0' || p[i] > '9'){
        flag = 1;
      }
    }
    if(p[a] != '-'){
      flag = 1;
    }
    for(int i = a + 1;i <= a + b;i++){
      if(p[i] < '0' || p[i] > '9'){
        flag = 1;
      }
    }
    if(flag == 0){
      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