Maximum Unique Substring Length

Given a string containing uppercase letters only, find the length of the longest substring that contains only unique characters. Write a function that takes a string and returns the length of the longest substring without repeating characters. Input Format: - A single line containing the string s (1 ≤ s ≤ 10^5). Output Format: - Output a single integer representing the length of the longest substring with all unique characters. Example: Input: ABDEFGABJKL Output: 7 In this example, the longest substring with all unique characters is "BDEFGAB" or any similar combination with maximum length.