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 C++ (Clang 10.0.0) (judge verdict: Accepted)

#include<iostream>
#include<string.h>

using namespace std;


 int main(void) {
 int k, a, b;

scanf("%d", &k);
 scanf("%d%d", &a, &b);
 int largest = (b / k) * k;
 if (a <= largest) {
 puts("OK");
} else {
 puts("NG");
}

return 0;
 }