#include<iostream>
#include<string>
using namespace std;
#define isnum(x) ((x)>='0'&&(x)<='9')
int main(void)
{
  int a,b,i;cin >> a >> b;
  string s; cin >> s;
  bool ok=true;
  for(i=0:i<a;i++) {
    if(!isnum(s[i])) {
      ok=false;
    }
  }
  if(s[a]!='-') ok=false;
  for(i=a+1;i<a+b+1;i++) {
    if(!isnum(s[i])) {
      ok=false;
    }
  }
  cout << ((ok?"Yes":"No")) << endl;
    
    
}