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>

int main(void){
  int A,B,K;
  
  scanf("%d", &A);
  scanf("%d", &B);
  scanf("%d", &K);
  
  int i,j;
  
  if(K>=1 && K<=1000 && A>=1 && A<=1000 && B>=1 && B<=1000 && A<=B && K<=B){
    for(i=1; i*K<=B; i++){
      if(A<=i*K && i*K<=B){
        puts("OK");
      if(A<=(i+1)*K && (i+1)*K<=B)
        break;
      }
    }
    
    for(j=1; j*K<=B; j++){
      if(B<(j+1)*K){
        if(A<=j*K && j*K<=B)
          break;
        else
          puts("NG");
      }
    }
    
  }
  else{
    puts("NG");
  }
  
  return 0;
}