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