The following languages are only available languages for the problems from the contest

Surprise Language Round #7:

FALSE

→ Virtual participation

Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ACM-ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

Chessboard is a board of n × n squares arranged in two alternating colors (black and white). Top left square is white. You are given board size n. Output an image of a chessboard, with black and white squares marked with '#' and '.' characters, respectively.

Input

The only line of input contains an integer n (1 ≤ n ≤ 9).