Fill the ? in equation 3 ? 3 ? 3 ? 3 ? 3 = 0 to make it true but allowed to use only two different types of operators? what would be those two operators and how will it be achieved.

Note: You are not allowed to add parentheses to the above expression

4 _ 4 _ 4 _ 4 = 20 In the equation, you can see that there are three blank spaces between four 4's.
You have to insert signs (+ -* /) between them in such a manner that the result equals 20.