Amazing to Not Amazing in JavaScript

Given a word s that starts with the letter a, return "not " followed by s without its first character. That's how "amazing" becomes "not mazing"!

Example 1:

Input: s = "amazing"
Output: "not mazing"
Explanation: Without its first character, "amazing" is "mazing". "not " goes in front of it, with its space.

Example 2:

Input: s = "aMAZING"
Output: "not MAZING"
Explanation: Only the first character is removed. The other characters stay as they are, upper case included.

Example 3:

Input: s = "an"
Output: "not n"
Explanation: Removing the "a" leaves just "n".

Constraints:

• s has at least 2 characters and starts with a lower-case a.
• s is one word made of English letters, lowercase or uppercase (no spaces).