Super Sale Challenge error

Question

Hello! I tried my code on the computer and it seems to work for the tests I can see from the Code Coach, but when I try the same code there, it works only for two of seven tests (and they're not the tests I tried). One of those give an error and I don't know why.

Examples are:
100.25,80.99,40.00

90,4,5

50,2,10 - it doesn't work on Code Coach

Here is my code:
https://code.sololearn.com/c6Lr6he9Y7hX

Answer 1

Provide the whole question, non pro members don't have access to the question.

Answer 2

Your favorite store is having a sale! You pay full price for the most expensive item that you get, but then you get 30% off of everything else in your purchase! How much are you going to save?
Sales tax is 7%.
Also, you leave anything below a dollar in your saving as a tip to the seller. If your saving is a round amount, you don't leave any tips.

Task:
Given the prices of items you want to purchase, determine how much you will save during your shopping!

Input Format:
An string of numbers separated by commas that represent the prices for all of the items that you want to purchase (without tax).

Output Format:
An integer number that represents the total savings that you got for shopping during the sale.

Sample Input:
100.25,80.99,40.00

Sample Output:
38