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.