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: Accepted)

/*--------------------------"SABUJ-JANA"------"JADAVPUR UNIVERSITY"--------*/
/*-------------------------------@greenindia-----------------------------------*/
//
//		  _____       _           _        _
//		 / ____|     | |         (_)      | |
//		| (___   __ _| |__  _   _ _       | | __ _ _ __   __ _
//		 \___ \ / _` | '_ \| | | | |  _   | |/ _` | '_ \ / _` |
//		 ____) | (_| | |_) | |_| | | | |__| | (_| | | | | (_| |
//		|_____/ \__,_|_.__/ \__,_| |  \____/ \__,_|_| |_|\__,_|
//		                        _/ |
//		                       |__/
/*---------------------- Magic. Do not touch.-----------------------------*/
/*------------------------------God is Great/\---------------------------------*/
#include <bits/stdc++.h>
using namespace std;
#define crap                     \
    ios::sync_with_stdio(false); \
    cin.tie(NULL);               \
    cout.tie(NULL)
//cout<<fixed<<showpoint<<setprecision(12)<<ans<<endl;
#define int long long int
#define double long double
#define PI acos(-1)
typedef vector<int> vi;
typedef vector<vector<int>> vvi;

signed main() {
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("error.txt", "w", stderr);
#endif
    crap;

    int k;
    cin >> k;

    int a, b;
    cin >> a >> b;

    double l = a / k;
    double r = b / k;

    if (r - l >= 1.00 or !(a % k) or !(b % k))
        cout << "OK";
    else {
        cout << "NG" << endl;
    }

    return 0;
}