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
fscanf(STDIN, "%d", $number); // STDIN から数値を読み込む
fscanf(STDIN, "%d %d", $number2,$number3); // STDIN から数値を読み込む
//$number = 10;
//$number2 = 15;
//$number3 = 30;

$x1 = (int)($number2 / $number);
$x2 = (int)($number3 / $number);
//echo "x1:$x1 x2:$x2";

for($start = $number2;$start<$number3;$start++){
for($i = $x1;$i < $x2; $i++){
$n = $i*$number;
//echo "n:$n ";
if($n > $number2 && $n < $number3) {
   $f = 1;
break;
  }else{
  $f = 0;
  }


}
}

if($f){
echo "OK";
}else{
echo "NG";
}


?>