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>
#include <stdlib.h>
#include <string.h>
 
int main(void){
	int K,A,B,i;
	char str[1000];
 
	fgets(str, sizeof(str), stdin);
	K=atoi(strtok(str," "));

	fgets(str, sizeof(str), stdin);
	A=atoi(strtok(str," "));
	B=atoi(strtok(NULL," "));

	for(i=A;i<B;i++){
		if(i%K ==0) break;
	}
	if( (i<B) || (B%K==0) ){
		printf("OK\n");
	}else{
		printf("NG\n");
	}

	return 0;
}