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)

#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<map>
#include<cstddef>
#include<queue>
#include<math.h>
#include<iomanip>
using namespace std;

int main()
{
    int A, B, K, ans = 0;
    cin >> K;
    cin >> A >> B;
    for(int i = A; i < B + 1; ++i){
        if(i % K == 0){
            ans++;
            break;
        }
    }
    if(ans == 1) cout << "OK" << endl;
    else cout << "NG" <<endl;
    return 0;
}