Convert Snake Case to Camel Case

Your team is transitioning a codebase where a colleague has been writing identifiers in snake case (e.g., "my_counter"), but your company’s coding standard requires lower camel case (e.g., "myCounter").

You are given a source string src. Return a new string in which every snake case segment found anywhere in src is converted to lower camel case. Do not limit your search to variable-like tokens—apply the transformation to any matching substring that follows the rules below.

• Words inside a snake case segment are delimited by single underscores. To convert to lower camel case, remove each underscore and uppercase the first letter of the word that follows it.
• Identifiers may begin with one or more underscores, and those leading underscores must be kept unchanged. For example, "__the_variable" shall become "__theVariable".
• Identifiers may end with trailing underscores, and those trailing underscores must be kept unchanged. For example, "the_variable__" shall become "theVariable__".
• Every snake case segment consists solely of lowercase English letters and the single underscores that separate the words; no other characters appear inside a segment.

Constraints:

• 0 ≤ src.length ≤ 10⁵

Example 1:

Example 2:

Example 3:

Examples

Example 1

Input: total_match_count
Output: totalMatchCount

Example 2

Input: __private_aux_field__
Output: __privateAuxField__