#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, i, j, p = 1;
  cin >> a >> b;
  for (i = 0; i < a; i++) {
    for (j = 0; j < b; j++) {
      if (i % 2 == 0)
        cout << "#";
      else {
        if (p && j == (b - 1)) {
          cout << "#";
        } else if (p == 0 && j == 0) {
          cout << "#";
        } else
          cout << ".";
      }
    }
    if (i % 2 == 1) p = !p;
    cout << endl;
  }
  return 0;
}
