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>
#define N 5

int main(void){
	int t,r0,r1,F = 1;
  	scanf("%d",&t);
  	scanf("%d",&r0);
  	scanf("%d",&r1);
  
  	
  	r0 = r0 / t;
	if(r0 != r1)
      	r0++;
  	//printf("r0 = %d\n",r0);
  
  	for(;r0 <= r1 / t;r0++){
      //printf("%d",r0 * t);
    	F = 0;
      	break;
    }
  	if(F)
      printf("NG\n");
  	else
      printf("OK\n");
  
 	 return 0;
}