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<stdio.h>

int main(void)
{
  int k,a,b;
  int ct=0;
  int i;
  scanf("%d",&k);
  scanf("%d %d",&a,&b);
    i=k;
  while(k<=b)
  {
    if(a<=k && k<=b)
    {
      ct++;
    }
    k=k+i;
  }
  if(ct>0) {
    printf("OK");
  }
    else {
      printf("NG");
    }
}