#include<bits/stdc++.h>
using namespace std;
int main()
{
  string a;
  int i,j,l,m,n,f=0;
  int m,n;
  cin>>m>>n;
  cin>>a;
  for(i=0;i<a.size();i++)
  {
     if(a[i]=='-')
        f=1;
      else if(f==1&&a[i]>=0&&a[i]<='9')
      f=2;

  }
    if(f==2)
        cout<<"Yes"<<endl;
    else
        cout<<"No"<<endl;


  return 0;
}
