Given the following code:
```
class A {
public void show() {
System.out.println("A");
}
}
class B extends A {
public void show() {
System.out.println("B");
}
}
```
What will be the output when the following code is executed?
```
A obj1 = new A();
B obj2 = new B();
A obj3 = new B();
obj1.show();
obj2.show();
obj3.show();
```