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>
using namespace std;
using ll = long long;
const int MOD = 1e9+7;

//vector<vector<int>> vec(縦,vector<int>(横));
/*deque<型> 配列の先頭にも用がある時はvectorの代わりに。
入力はstringでもらってからpush_back()*/
//printf("%書式指定" ,出力したい物);\nで改行



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