#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, i, j;
  cin >> n >> m;
  char arr[n][m];
  for (i = 0; i < n; i++)
    for (j = 0; j < m; j++) arr[i][j] = '.';
  for (i = 0; i < n; i += 2)
    for (j = 0; j < m; j++) arr[i][j] = '#';
  int flag = 1;
  for (i = 1; i < n; i += 2) {
    if (flag)
      arr[i][m - 1] = '#', flag = 0;
    else
      arr[i][0] = '#', flag = 1;
  }
  for (i = 0; i < n; i++) {
    for (j = 0; j < m; j++) {
      cout << arr[i][j];
    }
    cout << "\n";
  }
  return 0;
}
