## 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 nothing.

### Usage

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