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