A magic square is square grid filled with distinct positive integers such that each cell contains a different integer and the sum of the integers in each row, column and diagonal is equal.

Given a square 2D array, return true if it is a magic square.

Example:

magical([[7, 2, 3],
         [0, 4, 8],
         [5, 6, 1]]) --> true // Everything adds to 12

magical([[1, 1],
         [1, 1]])  --> false // duplicatre numbers used