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 PyPy3 (7.3.0) (judge verdict: Accepted)

import sys


def solve():
    readline = sys.stdin.buffer.readline
    mod = 10 ** 9 + 7
    k = int(readline())
    a, b = list(map(int, readline().split()))
    for i in range(a, b + 1):
        if i % k == 0:
            print("OK")
            exit()
    print("NG")


if __name__ == '__main__':
    solve()