Fractal
Time Limit: 1 Second Memory Limit: 32768 KB
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
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
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. Don't output any trailing spaces at the end of each line, or you may get an 'Presentation Error'!
Sample Input
1 2 3 4 -1
Sample Output
X - X X X X X - X X X X X X X X X X X X X X X X X X X X X X X X X - X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X -Submit
Source: Asia 2004, Shanghai (Mainland China), Preliminary