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,a,b,i;
  scanf("%d %d %d", &k, &a, &b);
  if(k == 1)
    printf("OK");
  else if(k > b)
    printf("NG");
  else if(k <= b - a)
    printf("OK");
  else {
    for(i=a;i<b;i++){
      if(i%k == 0){
        printf("OK");
        break;
      }
      if(i == b-1)
        printf("NG");
    }
  }
  return 0;
}