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>
#include <algorithm>
#include <iomanip>
#include"stdio.h"
#include <cstring>
#include<math.h>
#include<map>
#include<queue>
#include<stack>
#include"time.h"
#define MAX_INT  ((unsigned)(-1)>>1)
#define MIN_INT  (~MAX_INT)
#define db printf("where!\n");
#define pb push_back
using namespace std;
#define ll long long
ll gcd(ll x,ll y){return y ? gcd(y,x%y) : x;}
template<class T>inline void read(T &res){
char c;T flag=1;
while((c=getchar())<'0'||c>'9')if(c=='-')flag=-1;res=c-'0';
while((c=getchar())>='0'&&c<='9')res=res*10+c-'0';res*=flag;
}

int main()
{
    int a,b,c;
    cin>>a>>b>>c;
    if(c-b+1>=a||b/a!=c/a) cout<<"OK"<<endl;
    else cout<<"NG";
	return 0;
}