Fill in the matrix, in such a way that the sum of the numbers in each row (horizontally, vertically, and diagonally) is 264, even if you hold the matrix upside down. You are only allowed to use the digits 1, 6, 8, and 9, and each number may appear only once in the matrix.

You have to fill numbers in place of question marks. The numbers that you can use are 1, 3, 5, 7, 9, 11, 13 and 15. You can repeat the numbers if you like.