formula for counting how many different numbers are in a cell, separated by commas?

Hi all, pretty new to excel and looking for a specific formula that I fear probably doesn’t exist - I basically want a formula that counts how many different values are within one cell when each of these are separated by commas. For example if a cell said “24, 25, 26” I would want the result to be 3, if the cell said “42” I would want the result to be 1, if the cell is empty, result 0 etc. I hope that description makes sense - if anyone can tell me if a formula like this exists I would love to know!