Index of First Unique Character

You are given a string s consisting of lowercase English letters. Your task is to find and output the index of the first character in s that does not repeat anywhere else in the string.

If no such character exists, output \( -1 \).

Note: The index is 0-based. Also, the string may contain up to 10⁵ characters.

Example:

• For s = "leetcode", the result is 0 because 'l' appears only once.
• For s = "loveleetcode", the result is 2 because 'v' (at index 2) is the first unique character.
• For s = "aabb", the result is -1 since no character appears exactly once.

inputFormat

The input consists of a single line containing a non-empty string s of lowercase English letters.

outputFormat

Output a single integer which is the index of the first unique character in the input string s. If there is no unique character, output \( -1 \).

leetcode

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