Problem:
Score: 200 points

Problem Statement

The number 105 is quite special - it is odd but still it has eight divisors.
Now, your task is this: how many odd numbers with exactly eight positive divisors are there between 1 and N (inclusive)?

Constraints

N is an integer between 1 and 200 (inclusive).

Input

Input is given from Standard Input in the following format:

N

Output

Print the count.

Sample Input 1

105

Sample Output 1

1

Among the numbers between 1 and 105, the only number that is odd and has exactly eight divisors is 105.

Sample Input 2

7

Sample Output 2

0

1 has one divisor. 3, 5 and 7 are all prime and have two divisors. Thus, there is no number that satisfies the condition.

Solution in PHP7 (7.0.15) (judge verdict: Accepted)

<?php
// B
fscanf(STDIN, '%d', $n);
$ans = 0;
for ($i = 1; $i <= $n; $i += 2) {
    if (count(divisors($i)) === 8) $ans++;
}
echo $ans;

// 約数列挙
function divisors($max)
{
    $arr = [];
    $rmax = (int) floor(sqrt($max));
    for ($i = 1; $i <= $rmax; $i++) {
        if ($max % $i === 0) {
            $arr[] = $i;
            $arr[] = $max / $i;
        }
    }
    sort($arr);
    return array_unique($arr);
}