interface Answerer {
    public boolean getAnswer();
}
class abstract AbstractAnswerer implements Answerer {
    private boolean answer;
    private boolean input1;
    private boolean input2;
    public AbstractAnswerer(boolean input1, boolean input2) {
        this.input1 = input1;
        this.input2 = input2;
    }
    @Override public final boolean getAnswer() {
        this.answer = computeAnswer(input1, input2);
        return this.answer;
    }
    protected abstract boolean computeAnswer(boolean input1, boolean input2);
    
}
class ConcreteAnswerer extends AbstractAnswerer {
    public ConcreteAnswerer(boolean input1, boolean input2) {
        super(input1, input2);
    }
    @Override protected boolean computeAnswer(boolean input1, boolean input2) {
        if(input1 && !input2) return true;
        else return false;
    }
}