#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, i, j, s, r, m, ans;
  string x;
  cin >> n >> m;
  long long a[n + 1][m + 1];
  for (i = 1; i <= n; i++) {
    if (i % 2 == 1) {
      for (j = 0; j < m; j++) a[i][j] = 0;
    } else {
      for (j = 0; j < m; j++) a[i][j] = 1;
    }
  }
  for (i = 2; i <= n; i += 2) {
    if (i % 4 == 2) {
      a[i][m - 1] = 0;
    } else
      a[i][0] = 0;
  }
  for (i = 1; i <= n; i++) {
    for (j = 0; j < m; j++) {
      if (a[i][j] == 0)
        cout << "#";
      else
        cout << ".";
    }
    cout << endl;
  }
}
