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: Accepted)

#include <stdio.h>

int main(void){

    int K = 0;
    int A = 0;
    int B = 0;
    int flag = 0;
    scanf("%d", &K);
    scanf("%d %d", &A, &B);

    for (int i = A; i <= B; i++){
        if (i % K == 0){
            flag = 1;
        }
    }

    if (flag == 1){
        printf("OK\n");
    } else {
        printf("NG\n");        
    }


    return 0;
}