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
  $K = fgets(STDIN);
  $input_line = fgets(STDIN);
  $input = explode(" ", $input_line); 
  $A = $input[0];  // A
  $B = $input[1];  // B
	for(; ;){
    		if($A > $B){
        	  $result = 'NG';	
              break;
        	}
	        if($K < $A) {
                if($A % $K == 0) {
    				$result = 'OK';
            	    break;
				}
			}
      	$A++;
    	}          
    echo end($result);
?>