import java.util.Scanner;
import java.io.*;

public class Main {
public static void main(String args[]) {
Scanner cro=new Scanner(System.in);
BufferedReader c=new BufferedReader(new InputStreamReader(System.in));
String s,s1;
int A,B,i,C;
C=0;
A=cro.nextInt();
B=cro.nextInt();
s1=cro.nextLine();
s=cro.nextLine();
for(i=0;i<A;i++) if(Character.isDigit(s.charAt(i))) C++;
if(s.charAt(A)=='-') C++;
for(i=A+1;i<A+B+1;i++) if(Character.isDigit(s.charAt(i))) C++;
if(C==A+B+1) 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