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 Julia (1.4.0) (judge verdict: Accepted)

const teststr = 
"""
1
11 11
"""

function lines()
  Channel{String}(32) do ch
    ll = readlines()
    lines = isempty(ll) ? split(teststr, "\n") : ll
    for s in lines
      put!(ch, s)
    end
  end
end

quit() = exit(0)
in_1(ch) = parse(Int, take!(ch))
in_a(ch) = parse.(Int, split(take!(ch)))

function main()
  ch = lines()
  K = in_1(ch)
  A,B = in_a(ch)
  for i in A:B
    if mod(i, K) == 0
      println("OK")
      quit()
    end
  end
  println("NG")
end

main()