Problem:
Score : 100 points

Problem Statement

Takahashi has K 500-yen coins. (Yen is the currency of Japan.)
If these coins add up to X yen or more, print Yes; otherwise, print No.

Constraints

1 \leq K \leq 100

1 \leq X \leq 10^5

Input

Input is given from Standard Input in the following format:

K X

Output

If the coins add up to X yen or more, print Yes; otherwise, print No.

Sample Input 1

2 900

Sample Output 1

Yes

Two 500-yen coins add up to 1000 yen, which is not less than X = 900 yen.

Sample Input 2

1 501

Sample Output 2

No

One 500-yen coin is worth 500 yen, which is less than X = 501 yen.

Sample Input 3

4 2000

Sample Output 3

Yes

Four 500-yen coins add up to 2000 yen, which is not less than X = 2000 yen.

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

<?php

while ($line = fgets(STDIN)) {
   $tmp[] = trim($line);
}

// 配列の各要素をさらに分解します
foreach ($tmp as $key => $value) {
  $array[] = explode(" ", $value);
}
//命名

$k = $array[0][0];
$x = $array[0][1];

$sum = 500 * $k;

if ($sum >= $x) {
    echo 'Yes';
} else {
    echo 'No';
}


 ?>