P10458 Fractal
Description
A fractal is an object or quantity that displays self-similarity, in a somewhat technical sense, on all scales. The object need not exhibit exactly the same structure at all scales, but the same "type" of structures must appear on all scales.
A box fractal is defined as below :
- A box fractal of degree $1$ is simply X
- A box fractal of degree $2$ is
```
X X
X
X X
```
- If using $B(n - 1)$ to represent the box fractal of degree $n - 1$, then a box fractal of degree $n$ is defined recursively as following
```
B(n - 1) B(n - 1)
B(n - 1)
B(n - 1) B(n - 1)
```
Your task is to draw a box fractal of degree $n$.
Input Format
The input consists of several test cases. Each line of the input contains a positive integer $n$ which is no greater than $7$. The last line of input is a negative integer $-1$ indicating the end of input.
Output Format
For each test case, output the box fractal using the 'X' notation. Please notice that 'X' is an uppercase letter. Print a line with only a single dash after each test case.