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 <stdio.h>

int main(void) {
  int K;
  int A;
  int B;
  int C;
  scanf("%d", &K);
  scanf("%d", &A);
  scanf("%d", &B);
  for (int i = 1; K * i < B; i++) {
    if (A <= K * i && K * i <= B) {
      C = 1;
    } else {
      C = 0;
    }
  }
  if (C == 1) {
    printf("%s\n", "OK");
  } else {
    printf("%s\n", "NG");
  }
  return 0;
}