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: Accepted)

<?php
$input = (int)trim(fgets(STDIN));

list($start, $finish) = explode(' ', trim(fgets(STDIN)));

$count = 0;
for ($i = (int)$start; $i <= (int)$finish; $i++) {
    if ($i % $input === 0) {
        $count++;
        break;
    }
}

if ($count === 1) {
    echo 'OK';
} else {
    echo 'NG';
}