## switchcase

### Instructions

Write a program that takes two strings and displays, without doubles, the characters that appear in both strings, in the order they appear in the first one.

- The display will be followed by a `\n`.

- If the number of arguments is not 2, the program displays `\n`.

### Expected output

```console
student@ubuntu:~/piscine/test$ go build
student@ubuntu:~/piscine/test$ ./test "padinton" "paqefwtdjetyiytjneytjoeyjnejeyj"
padinto
student@ubuntu:~/piscine/test$ ./test ddf6vewg64f  twthgdwthdwfteewhrtag6h4ffdhsd
df6ewg4
student@ubuntu:~/piscine/test$
```