My .txt file is having lines like below:

```
1a
1aa
2a
2aa

```

I want to do a particular task for "a" side and another particular task for "aa" side. To be more precise and clear the task which I am doing for "a" side should not work for "aa" side and similarly the task which I am doing for "aa" side should not work for "a" side.

For exammple:

* For "aa" side, I want to go to one directory
* For "a" side, I want to go to more than one directory.

How can I do that in my script?