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)

/*                        ______
 _______   /\     |``\   |        |  /
    |     /  \    |__/   |____    |/
    |    / _ _\   |  \   |        |\
    |   /      \  |   \  |______  |  \

            Dept. of CSE
        Comilla  University

*/
#include<bits/stdc++.h>
#define pi 2*acos(0.0)
#define ll long long
#define FIO ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define Node struct node
#define spc " "
#define  E  2.71828182845904523536
#define pb push_back
#define pp pop_back
#define valid(nx,ny) nx>=0 && nx<n && ny>=0 && ny<m
#define ee endl
#define pii pair<int,int>
#define infinity 10000000000000000
#define mod 1000000007
int fx[]={0,0,+1,-1};
int fy[]={+1,-1,0,0};

using namespace std;
///check n=1;
///check corner case;
const int maX=1e5+1;
vector<ll>Graph[maX],cost[maX];
ll visit[maX];


int main()
{
   ll k,a,b;
   cin>>k>>a>>b;
   ll c=(b/k)*k;
   if(c>=a)cout<<"OK"<<endl;
   else cout<<"NG"<<endl;
return 0;
}