Count Unique Character Substrings

Given a string `s`, write a program to determine how many unique substrings exist within that string. A substring is defined as a contiguous sequence of characters within a string. The substrings should be counted without regard to case (e.g., 'abc' and 'ABC' are considered the same). The output should be the count of unique substrings. ### Input Format: - A single line containing the string `s` (1 <= |s| <= 1000). ### Output Format: - A single integer representing the count of unique substrings. ### Example: Input: abc Output: 6 Explanation: The unique substrings are: 'a', 'b', 'c', 'ab', 'bc', 'abc'.