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

    // AtCoder Beginner Contest 165
    // A - We Love Golf

    $k = in_int();
    list($a, $b) = in_ints();

    for ($i = $a; $i <= $b; $i++) {
        if ($i % $k == 0) {
            out('OK');
            break;
        }
    }
    if ($i > $b) {
        out('NG');
    }


    // -----------------------------------------------------
    function in() { return trim(fgets(STDIN)); }
    function in_int() { return (int)in(); }
    function in_vals() { return explode(' ', in()); }
    function in_ints() { return array_map('intval', in_vals()); }
    function out($s) { echo $s . PHP_EOL; }
    function yes() { out('Yes'); }
    function no() { out('No'); }