Print the chessboard#8550
You are given a chessboard of size n \times n. It is filled with numbers from to n^2 in the following way: the first \lceil n^2 / 2 \rceil numbers from to \lceil n^2 / 2 \rceil are written in the cells with an even sum of coordinates, from left to right and top to bottom. The remaining n^2 - \lceil n^2 / 2 \rceil numbers, from \lceil n^2 / 2 \rceil + 1 to n^2, are written in the cells with an odd sum of coordinates, also from left to right and top to bottom.
The operation means dividing by and rounding up to the nearest integer.
The input contains one integer (1 \le n \le 9).
Print the matrix — the chessboard as described above. Pay attention to alignment!
Example 1
Example 2