#include <bits/stdc++.h>
using namespace std;
int who(int n) {
  if (n < 5) {
    return n;
  } else {
    n -= 5;
    return who(n / 2);
  }
}
int main(int argc, char** argv) {
  int n, m;
  cin >> n >> m;
  vector<vector<char> > snake(n, vector<char>(m, '#'));
  for (int i = 1; i < n; i += 2) {
    for (int j = (i / 2) % 2; j < m - 1 + (i / 2) % 2; ++j) {
      snake[i][j] = '.';
    }
  }
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m; ++j) {
      cout << snake[i][j];
    }
    cout << "\n";
  }
  return 0;
}
