Spirals

Write a program that prints “spirals” of size $n \times n$ , as it is shown in the examples.

Input

Input consists of a sequence of strictly positive natural numbers, ended with zero.

Output

For each $n$ , print a spiral of size $n \times n$ . Note that in the bottom row and in the right column there are only ‘X’s. Print an empty line after each spiral.

Observation

A matrix is not needed to solve this problem, but use it for simplicity.

Problem information

Author: Unknown
Translator: Carlos Molina

Generation: 2026-01-25T11:13:52.987Z