=====Problem Statement=====
You are given an integer, N. Your task is to print an alphabet rangoli of size N. (Rangoli is a form of Indian folk art based on creation of patterns.)
Different sizes of alphabet rangoli are shown below:
#size 3
----c----
--c-b-c--
c-b-a-b-c
--c-b-c--
----c----
#size 5
--------e--------
------e-d-e------
----e-d-c-d-e----
--e-d-c-b-c-d-e--
e-d-c-b-a-b-c-d-e
--e-d-c-b-c-d-e--
----e-d-c-d-e----
------e-d-e------
--------e--------
#size 10
------------------j------------------
----------------j-i-j----------------
--------------j-i-h-i-j--------------
------------j-i-h-g-h-i-j------------
----------j-i-h-g-f-g-h-i-j----------
--------j-i-h-g-f-e-f-g-h-i-j--------
------j-i-h-g-f-e-d-e-f-g-h-i-j------
----j-i-h-g-f-e-d-c-d-e-f-g-h-i-j----
--j-i-h-g-f-e-d-c-b-c-d-e-f-g-h-i-j--
j-i-h-g-f-e-d-c-b-a-b-c-d-e-f-g-h-i-j
--j-i-h-g-f-e-d-c-b-c-d-e-f-g-h-i-j--
----j-i-h-g-f-e-d-c-d-e-f-g-h-i-j----
------j-i-h-g-f-e-d-e-f-g-h-i-j------
--------j-i-h-g-f-e-f-g-h-i-j--------
----------j-i-h-g-f-g-h-i-j----------
------------j-i-h-g-h-i-j------------
--------------j-i-h-i-j--------------
----------------j-i-j----------------
------------------j------------------
The center of the rangoli has the first alphabet letter a, and the boundary has the Nth alphabet letter (in alphabetical order).
=====Input Format=====
Only one line of input containing N, the size of the rangoli.
=====Constraints=====
0 < N < 27
=====Output Format=====
Print the alphabet rangoli in the format explained above.
n = int(input().strip())
w = (n-1) * 2 + ((n * 2) - 1)
#upper half
for i in range(1,n,1):
    number_of_letter = (i*2) - 1
    s = ''
    letter_value = 97 + n - 1
    for i in range(0,number_of_letter):
        if(i != 0):
            s += '-' 
        s += chr(letter_value) 
        if(i<(number_of_letter-1) / 2):
            letter_value = letter_value - 1
        else:
            letter_value = letter_value + 1            
    print((s.center(w,'-')))
    
    
#bottom half
for i in range(n,0,-1):
    number_of_letter = (i*2) - 1
    s = ''
    letter_value = 97 + n - 1
    for i in range(0,number_of_letter):
        if(i != 0):
            s += '-' 
        s += chr(letter_value) 
        if(i<(number_of_letter-1) / 2):
            letter_value = letter_value - 1
        else:
            letter_value = letter_value + 1            
    print((s.center(w,'-')))

n = int(input().strip())
w = (n-1) * 2 + ((n * 2) - 1)
#upper half
for i in range(1,n,1):
    number_of_letter = (i*2) - 1
    s = ''
    letter_value = 97 + n - 1
    for i in range(0,number_of_letter):
        if(i != 0):
            s += '-' 
        s += chr(letter_value) 
        if(i<(number_of_letter-1) / 2):
            letter_value = letter_value - 1
        else:
            letter_value = letter_value + 1            
    print((s.center(w,'-')))
    
    
#bottom half
for i in range(n,0,-1):
    number_of_letter = (i*2) - 1
    s = ''
    letter_value = 97 + n - 1
    for i in range(0,number_of_letter):
        if(i != 0):
            s += '-' 
        s += chr(letter_value) 
        if(i<(number_of_letter-1) / 2):
            letter_value = letter_value - 1
        else:
            letter_value = letter_value + 1            
    print((s.center(w,'-')))
