Write a bash script that takes a number as an argument and converts it into its corresponding raindrop sounds based on the following rules:

1. If the number is divisible by 3, add “Pling” to the result.
2. If the number is divisible by 5, add “Plang” to the result.
3. If the number is divisible by 7, add “Plong” to the result.
4. If the number is not divisible by 3, 5, or 7, the result should be the number as a string.

Example Output:

$ ./raindrop_sounds.sh 28
Plong
$ ./raindrop_sounds.sh 30
PlingPlang
$ ./raindrop_sounds.sh 34
34