What will be printed by the code below? (notice that there is no new-lines-enter- or whitespaces) #include using namespace std; class A ( public: A() (cout < < "+1";} -A() (cout < < "-1";} }; class B: public A ( public: }; B() (cout < < "+2";} -B() {cout < < "-2";) int main() { A a1; B b1; A a2 new A; B "b2 new B; delete a2; delete b2; return 0; 100%