Given an integer N.Create a string using only lowercase characters from a to z that follows the given rules.
When N is even:
Use N/2 characters from the beginning of a-z and N/2 characters from the ending of a-z.
When N is greater than 26,continue repeating the instructions until length of string becomes N.
When N is odd:
Case 1: If the sum of digits of N is even, Select (N+1)/2 characters from the beginning of a-z and (N-1)/2 characters from the ending of a-z.
Case 2: If the sum of digits of N is odd, Select (N-1)/2 characters from the beginning of a-z and (N+1)/2 characters from the ending of a-z.
When N is greater than 26,continue repeating the instructions until length of string becomes N.

Example 1:
Input:
N=21
Output:
abcdefghijpqrstuvwxyz
Explanation:
Since 21 is odd and sum of digits
of 21 is also odd,we take (21-1)/2=10
characters from the beginning and
(21+1)/2=11 characters from the
end of a-z.
Example 2:
Input:
N=28
Output:
abcdefghijklmnopqrstuvwxyzaz
Explanation:
Since 28>26, we keep repeating
the process until length of string becomes
28.

Your Task:
You don't need to read input or print anything. Your task is to complete the function BalancedString() which takes the integer N as input parameter and returns the string created using given procedures.

Expected Time Complexity: O(N)
Expected Auxiliary Space: O(1)

Constraints:
1 <= N <= 10^{5}

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