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