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: Runtime Error)

#include <stdio.h> 

int main(void)
{
    // int x;
    // scanf("%d", &x);
    // printf("%d\n", x);

    // long x;
    // scanf("%ld", &x);
    // printf("%ld\n", x);

    // char array[x];
    int k, a, b, ret=0, cnt=1;
    scanf("%d", &k);
    scanf("%d", &a);
    scanf("%d", &b);

    if (k > b)
        return 1;
    
    while (ret < a) {
        ret = (cnt++) * k;
        //printf("%d\n", ret);
    }

    if (ret <= b)
        printf("OK");
    else 
        printf("NGy");

    return 0;
}