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