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 <stdlib.h>
#include <cmath>
#include <cstdio>
#include <cstdint>
#include <string>
#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
using namespace std;

int main(){
  int K,A,B;
  cin >> K >> A >> B;
  string ans="NG";
  for(int i=A;i<=B;i++){
    if(i%K==0) ans="OK";
  }

  cout << ans << endl;
  
  return 0;
}