#include<cstdio>
#include<string>

using namespace std;

int main() {
	int a,b;
	string s;
	cin >> a >> b >> s;
	for(int i=0;i<a;i++){
	if(s[i]>='0' && s[i]<='9'){
		i++;
	}
	else{
		cout << "No" << endl;
		return 0;
	}
  }
	if(s[a] == '-'){
		for(int j=a+1;j<a+b;j++){
		if(s[j]>='0'&& s[j]<='9'){
			j++;
		}
		else{
			cout << "No" << endl;
			return 0;
		}
	  }
		cout << "Yes" << endl;
		return 0;
	}
	else{
		cout << "No" << endl;
		return 0;
	}

}