How to type certain characters in a code cell

Hello, I´m trying to write a program in a jupyter notebook to solve for angular diameter using certain input from the user. The inputs are Hubble´s Constant (H naught), the redshift (z), and the matter-density parameter (Omega sub m). What I'm trying to do is like this:

`s = input("What is the value of ___?")`

for each of these variables, but I can't figure out how to use the special characters (H naught and Omega sub m) in this type of cell. Is there perhaps a way to do this in a markdown cell?
I also apologize if I haven't gone about this correctly, it's my first time here.

The report concerns entering special characters in a Jupyter code cell or markdown cell, but it names no source file, test, or concrete documentation change. First clarify whether the expected guidance concerns Python identifiers, displayed mathematical notation, or both; done would be a documented, reproducible answer for these characters.

Written by the indexing model from the issue text.