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