How to check if all 9 buttons are pressed?

Hello. I have 9 buttons in my map and I want to create an event that triggers only if I have all 9 buttons pressed at the same time. What is the best way to go about this? Each button has it’s own Boolean variable of true or false for either pressed or not pressed respectively.

The easiest way would be to create an Int variable in the level BP and increase it by 1 every time a button is pressed (and decrease when unpressed).Then check if Int == 9.

You have to be careful not to get into a situation when pressing one button multiple times increases the Int to 9. You have to either have the functionality of buttons unpressing, or just make them impossible to be pressed more than once.