How To Make A Undo Button Because When Missclick Something

i am trying to make a really simple program to start with .It is for keeping score in a card game. The functionality of the program is 10 buttons(cards) that when you click them they dissapear and 4 buttons that when you click them they add or remove 1 point to two textboxs and one reset button that when you click it it resets everything.

I have done everything but now i want to make a undo button because when you missclick something it is really annoying you have to reset the whole thing and remember what exactly you had pressed before and this is not what i want. I googled a lot,i read a lot of threads here and in other forums but i mostly found web browsers undo buttons or i didnt understand what to do.