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;
#define lli long long int
#define rep(i, n) ;for (int i = 0;i < (int)(n);i++)
#define rep2(i, s, n) ;for (int i = s; i < (int)(n);i++)
#define ALL(vec)  (vec).begin(),(vec).end()
#define pi 3.1415926535897932384626433832795
#define MAX_INF 9223372036854775807
#define MIN_INF (922337203685477587+1)
#define sosuu 1000000007

int main() {
int A,B,K;
  cin >> K >> A  >> B;
  rep2(i,A, B+1 ){
  if(i%K==0){
  cout << "OK" << endl;
    return 0;
  }
  }
  cout << "NG" << endl;
}