Given a string, eliminate all “b” and “ac” in the string, replace them in-place and iterate over the string once.

Example 1:

Input: str = "aacbacc"
Output: ac
Explanation: Iterate once and remove
occurrence of "b" and "ac"

Example 2:

Input: str = "aacb"
Output: a
Explanation: Iterate once and remove
occurrence of "b" and "ac"

Your task:
Your task is to complete the function stringFilter() which takes a single string as input and returns the string. You need not take any input or print anything.
 

Expected Time Complexity: O(|s|)
Expected Auxiliary Space: O(1)

Constraints:
1 <= |S| <= 10⁵
String contains lower case alphabets