In this kata you must take an input string, reverse the order of the words, and reverse the order of the letters within the words.
But, as a bonus, every test input will end with a punctuation mark (! ? .) and the output should be returned with the mark at the end.
A few examples should help clarify:
```python
esrever("hello world.") == "dlrow olleh."
esrever("Much l33t?") == "t33l hcuM?"
esrever("tacocat!") == "tacocat!"
```
Quick Note: A string will always be passed in (though it may be empty) so no need for error-checking other types.
def esrever(s):
    return '' if not s else s[:-1][::-1]+s[-1]
def esrever(s):
    return '' if not s else s[:-1][::-1]+s[-1]