#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, mm, c = 1;
  cin >> n >> mm;
  for (int i = 1; i <= n; i++) {
    int m = mm;
    if (i % 2 == 0) {
      if (c % 2 == 0) {
        cout << "#";
        m--;
        while (m--) cout << ".";
      } else {
        m--;
        while (m--) cout << ".";
        cout << "#";
      }
      c++;
    } else
      while (m--) cout << "#";
    cout << endl;
  }
}
