import java.util.*;

import org.graalvm.compiler.nodes.extended.IntegerSwitchNode;
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 ebishu = true;
                for(int i = 0 ; i < a + b + 1 ; i++){
                        if(i != a){
                                if(s.charAt(i) < 48 || s.charAt(i) > 58){
                                        ebishu = false;
                                }
                        }
                }
                if(s.charAt(a) != '-') ebishu = false;
                if(ebishu) System.out.println("Yes");
                else System.out.println("No");
        }
}