Kuvunja Mfumo wa Tatu Dimensional katika PHP

Lakini kwa kuvunja mfumo wa tatu dimensional inahitajika kutumia vitanzi vitatu vilivyowekwa ndani. Hebu kwa mfano tuwe na mfumo kama huu:

php<?php
  $arr = [
    [
      ['a', 'b'],
      ['c', 'd'],
    ],
    [
      ['e', 'f'],
      ['g', 'h'],
    ],
    [
      ['i', 'j'],
      ['k', 'l'],
    ],
  ];
?>

Hebu tuonyeshe vipengele vyake vyote kwenye skrini:

php<?php
  foreach ($arr as $sub) {
    foreach ($sub as $subsub) {
      foreach ($subsub as $elem) {
        echo $elem;
      }
    }
  }
?>
Задание 1

Umepewa mfumo ufuatao:

php<?php
  $arr = [
    [
      [1, 2, 3],
      [6, 7, 8],
      [3, 8, 4],
      [6, 7, 9],
    ],
    [
      [9, 1, 2],
      [4, 5, 6],
    ],
    [
      [9, 1, 2],
      [4, 5, 6],
      [5, 6, 3],
    ],
  ];
?>

Kwa kutumia vitanzi vitatu vilivyowekwa ndani, tafuta jumla ya vipengele vya mfumo huu.