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 9.2.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <math.h>
#include <algorithm>
#include <string>
#include <string.h>
#include <queue>
#include <vector>
#include <set>
#include <map>
#include <tuple>
#include <stdlib.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
#define PI 3.14159265358979
typedef long long int ll;

const double pi=3.1415;
ll absc(ll a,ll b){return (a-b>0?a-b:b-a);
}
ll mini(ll a,ll b){return (a>b?b:a);}
ll gcd(ll a,ll b){
	if(a<b)swap(a,b);
	return (a%b?gcd(a%b,b):b);
}
int main()
{
   int a,b,c,k;
   string s,t;
   cin>>k>>a>>b;
   if(a/k!=b/k)cout<<"OK";
   else cout<<"NG";
}