#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b;
  	string s;
  	cin>>a>>b;
  	cin>>s;
  	if(s.at(a+1) == '-'){
    	c++;
    }
  for(int i=0;i<a;i++){
  	if(s.at(i) >= 48 && s.at(i)<= 57 ){
    	c++;
    }
  }
  for(int i=a+1;i<a+b+1;i++){
  	if(s.at(i) >= 48 && s.at(i)<= 57 ){
    	c++;
    }
  }
	if(c == 3){cout<<"Yes"<<"\n"; }
  	else { cout<<"No"<<"\n"; }
	return 0;
}