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

// 標準入力を一行ずつ配列に代入します
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);
}


for ($i = $array[1][0]; $i <= $array[1][1]; $i++) {
    if ($i % $array[0][0] == 0){
        echo "OK";
        break;
    }
    
    if($i+1 == $array[1][1]){
        echo "NG";
        break;
      }
}

?>