#include <bits/stdc++.h>
int main() {
  int h, w;
  int n;
  n = 0;
  int x, y;
  x = y = 0;
  scanf("%d %d", &h, &w);
  while (1) {
    if (n % 2 == 1) {
      printf(".");
    } else {
      printf("#");
    }
    n++;
    x++;
    if (x >= w) {
      printf("\n");
      n++;
      y++;
      x -= w;
    }
    if (y >= h) break;
  }
  return 0;
}
