please use jupyter notebook

question 1 part a

'''

write a program that prompts the user for their name and print length of the name

sample input: python

sample output: 6

'''

part b

'''

write a program that prompts the user of their name and then greets them with "hello, [name]!"

'''

part c

'''

write a python program that accepts a filename from the user and prints the extension of the file

sample input: assignment1.py

sample output: py

'''