a: x = 7 y = 6 z = 1
b: x = 8 y = 7 z = 1
c: x = 9 y = 4 z = 4
d: x = 14 y = 4 z = 4

public class ClassB extends ClassA {
    public int x;
    public int b;
    public int c;
    public ClassB(int x, int b, int c) {
        super(b,c);
        this.x = x;
    }
    
    public int methodA() {
        return a + b;
    }

    public int methodB() {
        z.changeMe();
    }
    
    public final int sum() {
        return x + b + c;
    }    
    public final int sum() {
        return x + b + c;
    }
}   

import java.awt.Graphics;
import java.awt.Color;

public class ColorTest extends javax.swing.JFrame {
    public void paint(Graphics g) {
        Color color= new Color(1.5f, 1.5f, 1.5f);
        g.setColor(color);
        g.drawRect(0,0,50,50);
    }
}

public class Question3 {
    // here is a partial list of java keywords, I assume this set is ALL the java keywords
    static String[] javaKeywords= {"if", "else", "while", "do", "switch",
                                       "case", "int", "float", "double", "char"}; 
    public static boolean isJavaIdentifier(String s) {
        if(!(Character.isLetter(s.charAt(0)) || (s.charAt(0) =='_') 
          || (s.charAt(0) == '$'))) {
            return false;
        }
        for(int i = 1; i < s.length(); i++) {
            if(!(Character.isLetter(s.charAt(i)) || (s.charAt(i) =='_') 
            || (s.charAt(i) == '$') || Character.isDigit(s.charAt(i)))) {
                return false;
            }
        }
        
        for(int i = 0; i < javaKeywords.length; i++ ) {
            if(s.equals(javaKeywords[i])) {
                return false;
            }
        }
        
        return true;
    }
    
    // for testing
    public static void main(String[] args) {
        System.out.println(isJavaIdentifier(args[0]));
    }
}