<?php

abstract class Bird
{
   abstract public function getName();
}

interface IFlayer
{
  public function fly(): int;
}

interface ISwimmer
{
  public function swim(): int;
}

class Duck extends Bird implements IFlayer, ISwimmer {
    public function getName(): string
    {
      return 'Donald Duck';
    }

    public function fly(): int
    {
      return 10;
    }

    public function swim() : int
    {
      return 3;
    }
}

$duck = new Duck();
echo $duck->getName() . PHP_EOL;
echo $duck->swim() . PHP_EOL;
echo $duck->fly() . PHP_EOL;