Write a program in string$\_$fun.py that does the following: Asks the user to input a string. Saves a file called "final$\_$exam.txt$".$ The file should contain as many lines as the user string has letters. The first line should contain the full string the user entered. The second line should contain all letters of the user string except the last one. The third line should contain all characters except the last two. This pattern should continue until the final line of the file, which will just be the first letter of the original user string. I think it's easier to just show an example. Here's my example solution running: $($base$)$ sniyaz@Sherdils$-$MacBook$-$Pro csci$-110-$fa$24-$lab$-$final $\%$ python$3$ string$\_$fun.py Enter a string: apple In this case, the user enters the string apple. Note that the Python program itself does not output anything to the terminal. It does, however, save this file $($final$\_$exam.txt$)$ to the same folder as string$\_$fun.py: apple appl app ap a You can also view this example file yourself: I've saved it as final$\_$exam$\_$example.txt in this folder. NOTE: You need to match this file format exactly for the auto$-$grader to work. Don't put a period or anything else like that after each line. Hint $1$: You probably want to take a look at string slicing from Lecture $12.$ You also probably should be using some kind of for loop in your solution. Hint $2$: Remember: you can use the len$()$ function to return the number of letters in a string $($the same way you would call it on a list to get the length of that list$).$ See this example in the Python interpreter: $>>>$ my$\_$string $=$ "apple" $>>>$ num$\_$letters $=$ len$($my$\_$string$)>>>$ print$($num$\_$letters$)5$