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: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;

#define imx INT_MAX
#define imn INT_MIN
#define llmx LLONG_MAX
#define llmn LLONG_MIN

#define fi first
#define se second
#define pb push_back
#define f_s(a) sort(a.begin(), a.end())
#define b_s(a) sort(a.rbegin(), a.rend())
#define p(a) cout<<a<<"\n"
// #define l(i, )
// #define rl(i, a, b) for(int i = a; i < b; i++)

/////////////////////GCD//////////////////////
ll gcd(ll a, ll b)
{
	if(b==0) return a;
	return gcd(b, a%b);
}


////////////////////SIEVE OF ERATOSTHENES//////////////////////
vector<int> sieveoferatosthenes(int n)
{
	vector<bool> prime(n+1, true);
	for(int i = 2; i <= sqrt(n); i++)
	{
		if(prime[i])
		{
			for(int j = i*i; j<=n; j+=i)
			{
				prime[j]=false;
			}
		}
	}
	vector<int> all_primes;
	for(int i = 2; i <=n; i++)
	{
		if(prime[i]) all_primes.pb(i);
	}
	return all_primes;
}



int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int k, a, b;
	cin>>k>>a>>b;
	if(b==a) cout<<"OK"<<endl;
	else if(b-a>=k)
	{
		cout<<"OK"<<endl;
	}
	else cout<<"NG"<<endl;

}