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 Pascal (FPC 3.0.4) (judge verdict: Accepted)

program main;
var
	k, a, b, count, i : integer;

begin
	read(k);
    readln(a, b);
    
    if k = 1
    	then writeln('OK')
        	else begin
            	count := 0;
            	for i := a to b do begin
                	if (frac(i / k) = 0)
                    	then count := count +1;
                 end;
     if count <> 0
     	then writeln('OK')
        		else writeln('NG');
    end;
end.