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 int
#define F first
#define S second
const ll mod = 1e9 + 7;
const ll INF = 10000000000000;
#define pb push_back
#define deb(x) cout << '>' << #x << ':' << x << endl;
#define fastio ios_base::sync_with_stdio(0); cin.tie(0);
using namespace std;
int main()
{
    fastio;
    ll k=0,a=0,b=0;
    cin>>k>>a>>b;
    for(ll i=a;i<=b;++i){
        if(i%k==0){
            cout<<"OK";
            return 0;
        }
    }
    cout<<"NG";
    return 0;
}