I have two text file "account.txt" and "customer.txt"

    **account.txt**

    876251251
    716126181
    888281211
    666615211
    787878787
    111212134

    **customer.txt**

    876251251
    716126181
    792342108
    792332668
    666615211
    760332429
    791952441
    676702288

I need to compare "account.txt" with "customer.txt".

- All account numbers from `account.txt` should be present in `customer.txt` file and if `customer.txt` is missing any "account number" then we should print out all those account numbers which are missing in `customer.txt`.
- And also all those extra customer numbers in `customer.txt` that are not present in `account.txt` file, I want to print that as well.

Output should be:

    Missing Account Number:
    888281211
    787878787
    111212134

    Extra Customer Number:
    792342108
    792332668
    760332429
    791952441
    676702288

Is this possible to do in linux? I started off like this but it only does the first case I want, not the second one? Also I need to print the output in the above format.

    comm -23 account.txt customer.txt
    
Note: It could be possible that there are some strings or empty lines in those files so we need to discard that in the comparison if we see any. We only need to compare valid numbers.