#include <bits/stdc++.h>
using namespace std;
int main() {
  int H, W, x, y;
  string a[300];
  string b[300];
  cin >> H >> W;
  for (int i = 0; i < 150; i++) {
    a[i * 2] = "#";
    a[i * 2 + 1] = ".";
    b[i * 2] = ".";
    b[i * 2 + 1] = "#";
  }
  a[300] = "#";
  b[300] = ".";
  x = W / 2;
  for (int j = 0; j < x; j++) {
    for (int k = 0; k < W; k++) {
      cout << a[k];
    }
    cout << endl;
    for (int l = 0; l < W; l++) {
      cout << b[l];
    }
    cout << endl;
  }
  if (W % 2 == 1) {
    for (int m = 0; m < W; m++) {
      cout << a[m];
    }
    cout << endl;
  }
  return 0;
}
