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 Python (3.8.2) (judge verdict: Accepted)

K=int(input())
A,B = map(int, input().split())
a=[]
i=1
while True:
    if K*i<=1000:
        a.append(K*i)
        i=i+1
    else:
        break
s=0
for i in a:
    

    if A<=i<=B:
        s=1
        
        break
if s==0:
    print("NG")
if s==1:
    print("OK")