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 <bits/stdc++.h>
#define ll long long
#define V vector<long long>
#define VV vector<vector<long long>>
#define VVV vector<vector<vector<long long>>>
#define P pair<ll,ll>
#define rep(i,n) for(ll (i)=0;(i)<(n);++(i))
using namespace std;

int main() {
    ll k;
    cin>>k;
    ll a,b;
    cin>>a>>b;
    for(ll i=a;i<=b;i++){
        if(i%k==0){
            cout<<"OK"<<endl;
            return 0;
        }
    }
    cout<<"NG"<<endl;
}