The $ boundary matcher matches an occurrence of a character/character class/group at the end of a line.

Task
Write a RegEx to match a test string, , under the following conditions:
- should consist of only lowercase and uppercase letters (no numbers or symbols).
- should end in
s.
This is a RegEx-only challenge, so you are not required to write any code.
Simply replace the blank (_________) with your RegEx pattern.