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<stdio.h>
int main()
{
  int a,b,k,m,i,c=0,j ;
   scanf("%d",&k);
   scanf("%d",&a);
   scanf("%d",&b);
  for(i=a;i<=b;i++)
  {
    m=i/k;
    j=m*k;
    if(i==j)
      c++;
  }
  if(c!=0)
     printf("OK");
  else
    printf("NG");
}