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