I think you need parenthesis around the parameters. e.g.
i.e. you have to press both Input1 and Input2 at the same time or alternatively Input3 and Input4 at the same time for it to register.
Code:
(Input1 & Input2) | (Input3 & Input4)i.e. you have to press both Input1 and Input2 at the same time or alternatively Input3 and Input4 at the same time for it to register.
