#include <cstdlib>
using namespace std;

int main(int argc,char** argv)
{
	int a, b;
	string s;
	cin >> a >> b >> s;
	for(int i = 0; i < a+b+1; i++){
		if(i < a){
			if(s[i]!='1' && s[i]!='2' && s[i]!='3' && s[i]!='4' && s[i]!='5'
				&&s[i]!='6' && s[i]!='7' && s[i]!='8' && s[i]!='9' && s[i]!='0'){
				cout << "No" <<endl;
				return 0;
			}
		}
		else if(i == a){
			if(s[i] != '-'){
				cout << "No" <<endl;
				return 0;
			}
		}
		else{
			if(s[i]!='1' && s[i]!='2' && s[i]!='3' && s[i]!='4' && s[i]!='5'
				&&s[i]!='6' && s[i]!='7' && s[i]!='8' && s[i]!='9' && s[i]!='0'){
				cout << "No" <<endl;
				return 0;
			}
		}
	}
	cout << "Yes" <<endl;


	return 0;

}