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>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep2(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define FOR(i) for(cin>>i;i>0;i--)
#define elif else if
#define pb push_back
#define ll long long
#define mp make_pair
#define all(x) x.begin(),x.end()
#define re(x) {cout<<x<<endl;return 0;}
//#define x first
//#define y second

using namespace std;
int a,b,c;
int main()
{
	cin>>a>>b>>c;
	if(b%a||c%a||b/a<c/a) re("OK")
	re("NG")
	return 0;}