#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,n=1;
	char c[15];
	cin>>a>>b;
	scanf("%c",c)
	for(int j=1;j<=1;j++){
		if(i!=a+1)
		{
			if(c[i]<'0'||c>'9')
		cout<<"No";
		return 0;
		}
		else if(a[i]!='-')
		{
			cout<<"No";
			return 0;
		}
	}
	cout<<"Yes";
}