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