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 S scanf
#define P printf
#define G getline
#define SZ size()
#define C clear()
#define B begin()
#define F front()
#define T top()
#define E end()
#define EM empty()
#define V vector
#define Q queue
#define DQ deque
#define PQ priority_queue
#define ST stack
#define FI first
#define SE second
#define PI acos(-1)
#define PS push
#define PP pop()
#define PSF push_front
#define PSB push_back
#define PPF pop_front()
#define PPB pop_back()
#define MP make_pair
#define LL long long int
#define ULL unsigned long long int
#define PII pair<int,int>
#define PSI pair<string,int>
#define PIS pair<int,string>
#define PLI pair<long long int,int>
#define PLL pair<long long int,long long int>
#define MII map<int,int>
#define MSI map<string,int>
#define MIS map<int,string>
#define MLI map<long long int,int>
#define FAST() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)





//int dx[]={-1,1,0,0};
//int dy[]={0,0,-1,1};
//int dx[]= {-1,0,1,-1,1,-1,0,1};
//int dy[]= {1,1,1,0,0,-1,-1,-1};






int main()
{
    FAST();

//    freopen("input.txt","r",stdin);
//    freopen("output.txt","w",stdout);

    int n,x,y;
    cin >> n >> x >> y;
    if((y/n)*n >= x)cout << "OK";
    else cout << "NG";
    return 0;
}