#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  cin >> n >> m;
  int snake[n][m];
  bool left = false, right = true;
  for (int i = 0; i < n; i++) {
    bool body = false;
    for (int j = 0; j < m; j++) {
      if (j == 0 && i % 2 != 0 && !body) {
        if (left) {
          cout << "#";
          right = true;
          left = false;
          body = true;
        } else {
          cout << ".";
        }
      } else if (j == m - 1 && i % 2 != 0 && !body) {
        if (right) {
          cout << "#";
          left = true;
          right = false;
          body = true;
        } else {
          cout << ".";
        }
      } else {
        if (i % 2 == 0) {
          cout << "#";
        } else {
          cout << ".";
        }
      }
    }
    cout << endl;
  }
  return 0;
}
