With a list of `Maybe a`, how to filter and take only the elements of the list which are not `Nothing`?

```hs
-- input
pas = [Just 3, Just 1, Just 5, Just 9, Nothing, Just 10, Nothing] :: [Maybe Int]

-- expected output
new_pas = [3, 1, 5, 9, 10]

```

I've tried different ways of using `map` and looked at `mapMaybe` but can't find the right combination.