Construct a Magic Square
To construct n x n magic square n x n ( n odd):
1. If i is in b[r][c], then i+1 goes in b[r’][c’], where r’,c’ determined as follows:
(a) try r’= r-1, if -1, then use r’=n-1.
(b) try c’= c+1, if n, then use c’= 0.
(c) if b[r’][c’] is already filled, use