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++ (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#define rep (i, n) for (int i = 1; i <= n; i++)

using namespace std;

int main() {
	int a, b, k;
	cin >> k >> a >> b;
	
	for (int i = a; i <= b; i++) {
		if (i % k == 0) {
			cout << "OK\n";
			return 0;
		}
	}
	
	cout << "NG\n";
	
	return 0;
}