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>
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = 1; i <= (int)(n); i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define fi first
#define se second
#define mp make_pair
using namespace std;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef vector<string> vs;
typedef vector<char> vc;
typedef long long ll;
typedef unsigned long long ull;

//const ll mod = 1000000007;
//const ll INF = mod * mod;

int main() {
    int k,a,b;
    cin >> k >> a >> b;
    bool ok = false;
    for(int i = a; i <= b; i++) {
        if(i % k == 0) {
            ok = true;
            break;
        }
    }
    if(ok) puts("OK");
    else puts("NG");
}