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 <iostream>
#include <sstream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <numeric>
#include <iomanip>
#include <string>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#pragma GCC target("avx512f,avx512dq,avx512cd,avx512bw,avx512vl")
#define pie 3.141592653589793238
using namespace std;

int main(void){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int k, a, b, ans=0;
  cin >> k;
  cin >> a >> b;
  for(int i=a; i<=b; i++){
    if(i%k==0) ans=1;
  }
  if(ans)cout << "OK" << endl;
  else cout << "NG" << endl;
  
  return 0;
}