Ard chapter3

I don't think the question was asking for a _single_ character to be conditionally case-swapped:

_...Have it convert *all* lowercase letters to uppercase, and *all* uppercase letters to lowercase, displaying the result._

I suspect it wants the user to enter in a sentence, like:
```
This sentence will achieve sentience.
```
And output something like:

```
tHIS SENTENCE WILL ACHIEVE SENTIENCE.
There were 32 case conversions. Goodbye!
```