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>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <unistd.h>
#include <math.h>
long long int ans=0;
//最大公約数
long long int getgcd(long long n, long long m)
{
  int r;
  if (n > m) {
    long long t = m;
    m = n;
    n = t;
  }
  while ((r = m % n) != 0) {
    m = n;
    n = r;
  }
return n;
}

//nの階乗を計算
long long factorial(long long n){
    long long int answer = 1;
while(n > 1){
  answer *= n;
  n--;
}
    return answer;
}

//組み合わせの数nCrを計算
long long calcNumOfCombination(long long  n, long long r){
    return factorial(n) / (factorial(r) * factorial(n-r));
}
 void yes(){
   printf("Yes\n");
 }

 void no(){
   printf("No\n");
 }

int main(int argc, char* argv[]){
	long long int a = 0, b = 0,c=0;
	scanf("%lld",&a);
  scanf("%lld %lld",&b,&c);
  for (int i = b; i <= c; i++) {
    if (i%a==0) {
      printf("OK\n");
      return 0;
    }
  }
  printf("NG" );
  return 0;
}