## displaya

### Instructions

Write a program that takes a string, and displays the first 'a' character it
encounters in it, followed by a newline. If there are no 'a' characters in the
string, the program just writes a newline. If the number of parameters is not
1, the program displays 'a' followed by a newline.

### Expected main and function for the program

### Expected output

```console
student@ubuntu:~/piscine/test$ go build
student@ubuntu:~/piscine/test$ ./test "abc"
a
student@ubuntu:~/piscine/test$ ./test "bcvbvA"
a
student@ubuntu:~/piscine/test$ ./test "nbv"
student@ubuntu:~/piscine/test$
```