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