# Find the Longest Even-Length Word Implement `longest_even_word(sentence)`. Words are separated by one or more spaces. Return the first word among those having the greatest positive even length. Return `"00"` when `sentence` is empty, contains only spaces, or contains no even-length word. The input is always a non-null string in every language. Examples: - `"Time to write great code"` returns `"Time"`. - `"a cat sun"` returns `"00"`. Constraints: at most `200000` characters; words contain English letters. Process the sentence in one pass over its words. ```hint Preserve first-on-tie behavior Update the answer only when a strictly longer eligible word appears. ```