Compare cell text to set list and show text differences

Hello. I need help solving the following issue. I am trying to write a function that will compare the text of cell "A2" to the text of cell "B2" and display cell "A2"'s text characters that didnt match from cell "B2" in column C. Can anyone help me out with writing this formula?

EX:

A2 = "Apple123"
B2 = "AppleS78"

Result = "S78"


Thank you in advance.