#include <bits/stdc++.h>
using namespace std;
const long long mei = (long long)1e9 + 7;
int main() {
  long long a, b, k;
  k = 0;
  cin >> a >> b;
  string s;
  cin >> s;
  for (long long i = 0; i < (long long)(s.size()); i++) {
    if (i != a && s[i] == '-') k++;
    if (i == a && s[i] != '-') k++;
  }
  if (k)
    cout << "Yes";
  else
    cout << "No";
  cout << endl;
}
