לפניכם המחלקות A, B, C:

java
1public class A {
2    public int num;
3
4    public A() {
5        this.num = 1;
6    }
7    public A(int num) {
8        this.num = num;
9    }
10    public int func (int val) {
11        return val * 2;
12    }
13    public int func (B other) {
14        return this.num - other.num;
15    }
16}
17
18public class B extends A {
19    public B() {
20        super(2);
21    }
22    public B(int val) {
23        super(val);
24        this.num = this.num + func (val);
25    }
26    public int func (A other) {
27        return this.num + (other.num * 10);
28    }
29    public int func (B other) {
30        return this.num + other.num;
31    }
32}
33
34public class C extends B {
35    public C(int val) {
36        this.num = this.num - val;
37    }
38    public int func (B other) {
39        return this.num * other.num;
40    }
41    public int func (C c) {
42        return this.num * 4;
43    }
44}