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 Perl (5.26.1) (judge verdict: Wrong Answer)

#!/usr/bin/perl
use Data::Dumper;

# 引数取り込み
my @a;
while ( my $line = <STDIN> ) {
    chomp($line);
    push @a, $line;
}

# 処理開始
my @b = split( / /,$a[1] );

my $str = "NG";
for ( my $i = $b[0], $i < $b[1] + 1, $i++ ) {
    $str = "OK" if ( $i % $a[0] == 0 );
}

print "$str";

1;