#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, m;
  cin >> n >> m;
  bool r = true;
  for (int i = 0; i < n; ++i) {
    string output = "";
    if ((i + 1) % 2 != 0) {
      cout << string(m, '#');
    } else {
      string s(m, '.');
      if (r)
        s = s.substr(0, s.length() - 1) + '#';
      else
        s = '#' + s.substr(1);
      r = !r;
      cout << s;
    }
    cout << "\n";
  }
  return 0;
}
