#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  while (cin >> n >> m) {
    int i;
    for (i = 1; i <= n; i++) {
      int k = m - 2, t = m;
      if (i % 2)
        while (t--) cout << "#";
      else {
        cout << (i % 4 ? "." : "#");
        while (k--) cout << ".";
        cout << (i % 4 ? "#" : ".");
      }
      cout << endl;
    }
  }
}
