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