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<string.h>
#include<stdlib.h>
#include<math.h>

#define mod 1000000007
#define limit 200001
typedef long long ll;
typedef long double ld;
#define rep(i,n) for(i = 0; i < n; i++)
#define max(a,b) {if(a>b){return a;}return b;}
#define min(a,b) {if(a<b){return a;}return b;}
int up_int(const void *a, const void *b){return *(int*)a - *(int*)b;}
int down_int(const void *a, const void *b){return *(int*)b - *(int*)a;}
int up_char(const void *left, const void *right) {return strcmp((char *)left,(char *)right);}

int main(){
    int k,flag = 0;
    int a,b,i;
    
    scanf("%d",&k);
    scanf("%d %d",&a,&b);
    
    for(i = a; i <= b; i++){
        if(i % k == 0){
            flag = 1;
            break;
        }
    }
    if(flag == 1) printf("OK\n");
    else printf("NO\n");
    return 0;
}