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>
#include<math.h>
#define T 100000

int main(){
    
	long int A,B,N;
    scanf("%ld %ld %ld",&A,&B,&N);

    int i;
    int ans[T];
    for(i=1;i<T;i++){
        ans[i-1] = A*i/B - A*(i/B);
    }

    int temp=0;
    for(i=0;i<N-1;i++){
        if(temp<ans[i]){temp = ans[i];}
    }

printf("%d",temp);

return 0;

}