Longest Unique Substring

Given a string \(s\), find the length of the longest substring that contains only unique characters. In other words, you are to determine the maximum value of \(j - i + 1\) such that the substring \(s[i \ldots j]\) does not contain any duplicate characters.

This problem can be solved efficiently using the sliding window technique. The key is to maintain a window with unique characters and update the window whenever a repeated character is encountered. The update formula for the current window length is \(\text{current length} = end - start + 1\), where start and end mark the boundaries of the current substring.

inputFormat

The input consists of a single line containing the string \(s\). The string may include spaces and other printable characters.

outputFormat

Output a single integer representing the length of the longest substring of \(s\) that contains only unique characters.

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3