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 Kotlin (1.3.71) (judge verdict: Accepted)

import java.util.*
import java.math.*
import kotlin.math.*

fun readLn()=readLine()!!
fun readInt()=readLn().toInt()
fun readInts()=readLn().split(" ").map{it.toInt()}
fun readLong()=readLn().toLong()
fun readLongs()=readLn().split(" ").map{it.toLong()}

val out=mutableListOf<String>()
fun printLine(s:String){out.add(s)}
fun output(){println(out.joinToString("\n"))}

fun main(){
    val t=1
    repeat(t){
        var k=readInt()
        var (a,b)=readInts()
        var ans=true
        if((a-1)/k==b/k)ans=false
        if(ans)printLine("OK")
        else printLine("NG")
    }
    output()
}