PROGRAMMING:Letter matrix
This problem requires from the lower left corner, according to the order of the alphabet S-type print by the small letters composed of the letter matrix.
###Input format:
Enter a positive integer n (1 = < n < = 1000).
###Output format:
Output the matrix composed of N rows and N columns of lowercase letters in alphabetic order, start from the upper right corner, S-type cycle printing, the letters are separated by a space, and there is no space after the last letter of each line.
###Input example:
```in
six
```
###Output example:
```out
j y x m l a
i z w n k b
h a v o j c
g b u p i d
f c t q h e
e d s r g f
```
answer：If there is no answer, please comment
###Input format:
Enter a positive integer n (1 = < n < = 1000).
###Output format:
Output the matrix composed of N rows and N columns of lowercase letters in alphabetic order, start from the upper right corner, S-type cycle printing, the letters are separated by a space, and there is no space after the last letter of each line.
###Input example:
```in
six
```
###Output example:
```out
j y x m l a
i z w n k b
h a v o j c
g b u p i d
f c t q h e
e d s r g f
```
answer：If there is no answer, please comment