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++ (Clang 10.0.0) (judge verdict: Wrong Answer)

#include<iostream>
using namespace std;

int main(void){
  long long a,b,num,max=0;
  cin>>a>>b>>num;
  if((b-1)>num){
    max =((a*num)/b)-a*(num/b);
  }
    else{
    num=b-1;
    max=((a*num)/b)-a*(num/b);
  }
  cout<<max;
  return 0;
}