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