Longest Unique Substring

Given a string s, find the length of the longest substring without repeating characters.

The problem can be formulated as follows:

Find the maximum value of \( j - i + 1 \) such that all characters in the substring \( s[i \ldots j] \) are distinct.

For example:

• If s = "abcabcbb", the answer is 3 (the substring "abc").
• If s = "bbbbb", the answer is 1 (the substring "b").
• If s = "pwwkew", the answer is 3 (the substring "wke").

Please note that the input is provided via stdin and the answer must be printed to stdout.

inputFormat

The input consists of a single line containing the string s. The string may be empty and will consist of printable ASCII characters.

outputFormat

Output a single integer which is the length of the longest substring of s that has no repeating characters.

abcabcbb

3