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 endl '\n'
typedef long long LL;
using namespace std;

int main(){
  ios::sync_with_stdio(false); cin.tie(0);

  int t = 1; //cin >> t;
  while (t--){
    int k, a, b; cin >> k >> a >> b;
    int ans = false;
    for (int i = k; i <= b; i += k){
      if (a <= i && i <= b) ans = true;
    }
    cout << (ans ? "OK" : "NG") << endl;
  }
}