#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  cin >> n >> m;
  for (int r = 1; r <= n; r++) {
    for (int c = 1; c <= m; c++) {
      if ((r % 2 != 0) || (r % 4 == 0 && c == 1) ||
          (r % 2 == 0 && r % 4 != 0 && c == m))
        cout << "#";
      else
        cout << ".";
    }
    cout << endl;
  }
  return 0;
}
