Get Final String

Problem Overview

• Remove all occurrences of the substring "AWS" from an uppercase string repeatedly until none remain, then return the final string.
• Input: string s (length 1 to 100000, uppercase only). Output: the resulting string, or "-1" if it becomes empty.
• Applies to string processing tasks such as text cleanup and parsing.
• Asked in Ibm interviews; a classic coding interview problem and interview question.