#include <bits/stdc++.h>
using namespace std;
int main() {
  int n = 0;
  int k = 0;
  int i = 0;
  cin >> n >> k;
  char* mas = new char[n];
  for (int g = 0; g < n; g++) cin >> mas[g];
  while (i != n - 1) {
    if (mas[i + 1] == 46) {
      ++i;
      continue;
    } else {
      if (mas[i + 1] == 35) {
        int j = 1;
        while (mas[i + j] != 46 && j < k) {
          ++j;
        }
        i += j;
        if (mas[i] != 46) {
          cout << "NO" << endl;
          return 0;
        }
      }
    }
  }
  cout << "YES" << endl;
  return 0;
}
