CAPS LOCK DAY is over!

October 22nd is CAPS LOCK DAY. Apart from that day, every sentence should be lowercase, so write a function to normalize a sentence.

Create a function that takes a string. If the string is all uppercase characters, convert it to lowercase and add an exclamation mark at the end.

Examples

normalize("CAPS LOCK DAY IS OVER") ➞ "Caps lock day is over!"

normalize("Today is not caps lock day.") ➞ "Today is not caps lock day."

normalize("Let us stay calm, no need to panic.") ➞ "Let us stay calm, no need to panic."

Notes

Each string is a sentence and should start with an uppercase character.