Problem:
Score : 100 points

Problem Statement

You will turn on the air conditioner if, and only if, the temperature of the room is 30 degrees Celsius or above.

The current temperature of the room is X degrees Celsius. Will you turn on the air conditioner?

Constraints

-40 \leq X \leq 40

X is an integer.

Input

Input is given from Standard Input in the following format:

X

Output

Print Yes if you will turn on the air conditioner; print No otherwise.

Sample Input 1

25

Sample Output 1

No

Sample Input 2

30

Sample Output 2

Yes

Solution in PHP (7.4.4) (judge verdict: Wrong Answer)

<?php
$k = trim(fgets(STDIN));

if ($k % 2 == 0) {
    echo "-1".PHP_EOL;
    exit;
}

$a = 7;
for($i = 1; $i < 1000000; ++$i) {
    if ($a % $k == 0) {
        echo $i.PHP_EOL;
        exit;
    }
    $a = $a % $k; // $kで割り切れるときは割っておく（桁あふれ防止？）
    $a = $a * 10 + 7;
}

echo "-1".PHP_EOL;