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