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 ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define piii pair<int,pii>
#define pll pair<ll,ll>
#define plii pair<ll,pii>
#define vi vector<int>
#define ff first
#define ss second
#define mp make_pair
#define pb push_back
#define mx 100001
#define eps 0.00000000001
#define mod 1000000007
#define pi acos(-1)
#define inf 100000000
#define loop(i,b,n) for(int i=b;i<n;++i)
#define rev_loop(i,b,n) for(int i=b;i>=n;--i)
#define fio ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
using namespace std;
int main()
{
    fio;
    int k;
    cin>>k;
    int a,b;
    cin>>a>>b;
    bool chk = false;
    for(int i=a;i<=b;i++)
    {
        if(i%k==0)
        {
            chk = true;
            break;
        }
    }
    if(chk)
        cout<<"OK\n";
    else
        cout<<"NG\n";
    return 0;
}