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>
typedef long long ll;
#define pii pair<int,int>
#define ff first
#define ss second
using namespace std;
void fast()
{
ios::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
}

int main()
{
    fast();
    int x,a,b;
    cin>>x>>a>>b;
    if(a%x==0||b%x==0)
    cout<<"OK\n";
    else if(x*((a/x)+1)>=a&&x*((a/x)+1)<=b)
        cout<<"OK\n";
    else
        cout<<"NG\n";

   
}