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 Ruby (2.7.1) (judge verdict: Accepted)

K, A, B = $stdin.read.split(/\n| /).map(&:to_i)

if B - A >= K
  puts "OK"
else
  a = A%K
  b = B%K

  if a == 0 || b == 0
    puts "OK"
  else
    if (B/K)-(A/K) >= 1
      puts "OK"
    else
      puts "NG"
    end
  end
end