Unique Substrings Check

Given a string S, determine whether all of its possible substrings are unique. A substring is defined as a contiguous sequence of characters within the string, and for a string of length n, there are \(\frac{n(n+1)}{2}\) possible substrings (including the string itself and single characters).

The answer should be Unique if no substring appears more than once, and Not Unique otherwise. Note that an empty string is considered to have all unique substrings.

Example:

• Input: "abcd" → Output: Unique
• Input: "aa" → Output: Not Unique

inputFormat

The input consists of a single line containing the string S. The string may include letters, digits, and special characters.

outputFormat

Output a single line: Unique if all substrings of the input string are unique, otherwise Not Unique.

abcd

Unique