package com.company;

import java.util.*;
import java.lang.*;
import java.io.*;

class A1 {
    int foo() {
        return 1;
    }

    int res1() {
        return this.foo();
    }
}

class A2 extends A1 {
    @Override
    int foo() {
        return 2;
    }

}

class A3 extends A2 {
    int res2() {
        return this.res1();
    }

    int res3() {
        return super.foo();
    }
    @Override
    int foo(){
        return 3;
    }
}

class A4 extends A3 {
    @Override
    int foo() {
        return 4;
    }
}

/* Name of the class has to be "Main" only if the class is public. */
public class Main {
    public static void main(String[] args) throws java.lang.Exception {
        A1 a1 = new A1();

        A2 a2 = new A2();
        A3 a3 = new A3();
        A4 a4 = new A4();
        System.out.println(a4.res3());
    }
}