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

$k = array_shift($tmp);

$a = explode(" " ,$tmp[0]);

$b = $a[0];
$c = $a[1];

$i=1;
while($i<=$c){
    if($i%$k == 0){
        if($i>=$b){
           $result[] = $i; 
        }
    }
    $i++;
}
if(isset($result)){
    echo "OK";
}else{
    echo "NG";
}
?>