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 Go (1.14.1) (judge verdict: Accepted)

package main

import "fmt"

func main() {
	var k, a, b int
	fmt.Scan(&k, &a, &b)
	if flag(a, b, k) {
		fmt.Println("OK")
	} else {
		fmt.Println("NG")
	}
}

func flag(a, b, k int) bool {
	for i := a; i <= b; i++ {
		if i%k == 0 {
			return true
		}
	}
	return false
}