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)

//T1 
#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<map>
#include<iostream>
#include<queue>
#include<set>
#include<stack>
#include<string>
#include<vector>
using namespace std;
#define ll long long
#define f(i,a,b) for(int i=a;i<=b;i++)
inline ll read(){
   int s=0,w=1;
   char ch=getchar();
   while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
   while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
   return s*w;
}
#define d read()
ll l,r,k;
int main(){
	k=d,l=d,r=d;
	f(i,l,r)
		if(i%k==0){cout<<"OK";return 0;}
	cout<<"NG";
	return 0;
}