What elements are contained in the following set after this code executes?

Set set = new HashSet<>();

set.add(74);

set.add(12);

set.add(74);

set.add(74);

set.add(43);

set.remove(74);

set.remove(999);

set.remove(43);

set.add(32);

set.add(12);

set.add(9);

set.add(999);