<?php

$pages = [
	'html1.html' => [1,5,60],
	'html2.html' => [50,40,20],
	'html3.html' => [500,3,2],
	];
	
$input = 3;

foreach($pages as $key => $value) {
    if(array_search($input,$value))
    {
    	echo "$input found in $key";
    }
    
    
    
    
}