#include <bits/stdc++.h>
using namespace std;
int main() {
  bool flag = true;
  while (flag == true) {
    int h, w = 0;
    cin >> h >> w;
    if (h != 0 && w != 0) {
      for (int i = 0; i < w; i++) {
        for (int j = 0; j < h; j++) {
          if ((i + j) % 2 == 0) {
            cout << "#";
          } else {
            cout << ",";
          }
        }
        cout << endl;
      }
    } else {
      flag = false;
    }
  }
}
