#include <cstdio>
#include <string>
#include <vector>
#include <iostream>
using namespace std;


string str1;


int main(int argc, char const *argv[])
{
	int a,b; cin>>a>>b;
	cin>>str1;
	int len=str1.length();
	for(int i=0 ;i<len; i++){
		if(str1[a]=='-')
			cout<<"Yes"<<endl;
		else
			cout<<"No"<<endl;

		break;
	}


