<?php
header("Content-Type: text/plain; charset=utf-8");
?> 
<?php

error_reporting(-1);
mb_internal_encoding('utf-8');

function getPyramid($n)
{
    $x = 0;
    $y = 0;
    for ($i = 1; $y <= $n; $i++) {
        $x += $i;
        $y += $x;
        
    }
    if ($n <= $y) {
        $i -= 2;
    }
    return $i;
}

echo getPyramid(84);
echo "\n";
echo getPyramid(3);
echo "\n";
echo getPyramid(5);
echo "\n";
echo getPyramid(14);
echo "\n";
echo getPyramid(23);
echo "\n";