Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 9948 Accepted: 4570 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 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. 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

Source Shanghai 2004 Preliminary