#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, m;
  int count = 0;
  cin >> n >> m;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      if (i % 2) {
        cout << "#";
      } else {
        if (j == 1) {
          if (count % 2) {
            cout << "#";
            count = 0;
          } else {
            cout << ".";
            count = 1;
          }
        } else if (j == m) {
          if (count % 2) {
            cout << "#";
            count = 1;
          } else {
            cout << ".";
            count = 0;
          }
        } else
          cout << ".";
      }
    }
    cout << endl;
  }
  return 0;
}
