<?php

class Prnt {
  public function __construct() {
    echo 'In Prnt';
  }
}

class A extends Prnt {
  public function __construct() {
    echo 'In A';
  }
}

class B extends A {
  public function __construct() {
    echo 'In B' . PHP_EOL;
    Prnt::__construct();
  }
}

new B();