#include <iostream>
using namespace std;
int main(){
	int a,b;
	int d=0;
	string s;
	cin>>a>>b>>s;
	for(int i=0;i<s.size();i++){
		if(s[i]=='0'||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')
		continue;
		else
		d++;
	}
if(s[a]=='-'&&s.size()==(a+b+1)&&a>=1&&a<=5&&b>1&&b<=5&&(d-1)==0)
cout<<"Yes"<<endl;
else
cout<<"No"<<endl;
	
	return 0;
}