## switchcase

### Instructions

Write a program that takes a `string` and reverses the case of all its letters.

-   Other characters remain unchanged.

-   The result must be followed by a newline (`'\n'`).

-   If the number of arguments is different from 1, the program displays a newline (`'\n'`).

### Usage

```console
student@ubuntu:~/piscine-go/test$ go build
student@ubuntu:~/piscine-go/test$ ./test "SometHingS iS WronG"
sOMEThINGs Is wRONg
student@ubuntu:~/piscine-go/test$ ./test

student@ubuntu:~/piscine-go/test$
```