#include <bits/stdc++.h>
using namespace std;
int columns;
void printM(char ch) {
  for (int i = 0; i < columns - 1; ++i) {
    cout << ch;
  }
}
int main(int argc, char const *argv[]) {
  int rows;
  cin >> rows >> columns;
  for (int i = 1; i <= rows; ++i) {
    if (i % 2 == 1) {
      cout << "#";
      printM('#');
    } else if (i % 4 == 2) {
      printM('.');
      cout << "#";
    } else {
      cout << "#";
      printM('.');
    }
    cout << endl;
  }
  return 0;
}
