Number Spirals [Don Piele, 1982]

The numbers in the square below (for which N=5) form a spiral pattern
that starts in the middle and continues in an obvious way:

21 20 19 18 17
22  7  6  5 16
23  8  1  4 15
24  9  2  3 14
25 10 11 12 13

Deduce the pattern and write a program to generate number spirals
of size N (N is odd and 1 <= N < 30). Print space-separated two
digit numbers for the spiral elements when N <= 9 and three digit
numbers when N >= 11.

Note to Level One competitors: This might be harder than it looks!

PROBLEM NAME: spiral

INPUT FORMAT:

* Line 1: N

SAMPLE INPUT (file spiral.in):

5

OUTPUT FORMAT:

* Lines 1..N: A spiral in the shape as shown above

SAMPLE OUTPUT (file spiral.out):

21 20 19 18 17
22  7  6  5 16
23  8  1  4 15
24  9  2  3 14
25 10 11 12 13

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