Problem:
Score: 100 points

Problem Statement

Takahashi the Jumbo will practice golf.

His objective is to get a carry distance that is a multiple of K, while he can only make a carry distance of between A and B (inclusive).

If he can achieve the objective, print OK; if he cannot, print NG.

Constraints

All values in input are integers.

1 \leq A \leq B \leq 1000

1 \leq K \leq 1000

Input

Input is given from Standard Input in the following format:

K
A B

Output

If he can achieve the objective, print OK; if he cannot, print NG.

Sample Input 1

7
500 600

Sample Output 1

OK

Among the multiples of 7, for example, 567 lies between 500 and 600.

Sample Input 2

4
5 7

Sample Output 2

NG

No multiple of 4 lies between 5 and 7.

Sample Input 3

1
11 11

Sample Output 3

OK

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

<?php

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

$K = $stdinDatas[0];
$array = explode(" ", $stdinDatas[1]);
$A = $array[0];
$B = $array[1];

if ($K <= $B) {
    for ($j = 1; $j < 1000; $j++) {

        if ($j * $K >=$A && $j * $K <= $B) {
            exit("OK");
        }
    }
}
exit("NO");