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 (Clang 10.0.0) (judge verdict: Accepted)

#include <math.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void) {
  int i;
  int K,A,B;
  long cnt = 0;
  scanf("%d", &K);
  scanf("%d %d", &A, &B);
  if (K == 1) {
    printf("OK\n");
    return 0;
  }
  if (A == B) {
    if ((A / K )*K == A) {
      printf("OK\n");
    } else {
      printf("NG\n");
    }
    return 0;

  }
  int c;
  if (A % K == 0) {
    c = (A / K);
  } else {
    c = (A / K) + 1;
  }
    int d = B / K;
    if (c <= d) {
      printf("OK\n");
    } else {
      printf("NG\n");
    }
    return 0;
  }