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