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: Runtime Error)

#include<stdio.h>
#include<math.h>
int main()
{
	int a,b,n,temp,i,arr[100];
	scanf("%d%d%d",&a,&b,&n);
	for(i=0;i<=n;i++)
	{
		arr[i]=(floor((a*i)/b)-(a*(floor(i/b))));	
	}
	for(i=0;i<=n;i++)
	{
		if(arr[0]<arr[i])
		{
			temp=arr[0];
			arr[0]=arr[i];
			arr[i]=temp;
		}
	}
	printf("%d",arr[0]);
	return 0;
}