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(){
  int unused __attribute__((unused));
  int K, A, B, i, tmpK = 0, t = 0;
  unused = scanf("%d", &K);
  unused = scanf("%d %d", &A, &B);

  i=1;
  while(tmpK <= 1000){
    tmpK = i*K;
    if(A <= tmpK && tmpK <= B) t = 1;
    i++;
  }
  if(t==1) printf("OK");
  else printf("NG");
  return 0;
}