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)

/*
 * author: calgagi
 *         Calvin Gagliano 
 */
#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define ull unsigned long long
#define ii pair<int, int>
#define ar array
#define f first
#define s second
#define dd long double

int main() {
    ios_base::sync_with_stdio(false);  
    cin.tie(NULL);
    srand(chrono::steady_clock::now().time_since_epoch().count()); 
    // freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); 
    
    int k, a, b;
    cin >> k >> a >> b;

    if ((b/k)*k >= a) {
        cout << "OK" << endl;
    } else {
        cout << "NG" << endl;
    }

    return 0;
}