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)

#!/usr/bin/env -S JULIA_VERSION=1.4.0 julia
# contest: abc165, problem: abc165_a, alphabet: A
const YES = "OK"
macro Y() :( println(YES); return ) end
const NO = "NG"
macro N() :( println(NO); return ) end

function solve(K::Int, A::Int, B::Int)
  for i in A:B
    i % K==0 && @Y
  end
  @N
end

function main()
  tokens = Channel{String}(32)
  Task() do
    for line in eachline(@static VERSION < v"0.6" ? STDIN : stdin)
      startswith(line, '\0') && break
      for token in split(chomp(line))
        put!(tokens, token)
      end
    end
    close(tokens)
  end |> schedule
  K = parse(Int, take!(tokens))
  A = parse(Int, take!(tokens))
  B = parse(Int, take!(tokens))
  solve(K, A, B)
end

if isempty(get(ENV, "ATCODER_LOCAL", ""))
  isempty(ARGS) && main()
else
  @eval begin
    const samples = [("7\n500 600", "OK"), ("4\n5 7", "NG"), ("1\n11 11", "OK")]
    function test(sampleids...)
      isempty(sampleids) && return test(collect(1:length(samples))...)
      ostdin, ostdout = @static VERSION < v"0.6" ? (STDIN, STDOUT) : (stdin, stdout)
      rd, wr = first(redirect_stdout()), last(redirect_stdin())
      try
        map(sampleids) do sampleid
          input, output = samples[sampleid]
          print(ostdout, "Testing sample #$(sampleid)..."); flush(ostdout)
          println(wr, input)
          println(wr, "\0")
          t = @elapsed main()
          println()
          result = strip(String(readavailable(rd)))
          if result == output
            println(ostdout, "OK ($t sec).")
            true
          else
            println(ostdout, "ERROR ($t sec)")
            println(ostdout, "== expected ==\n$output")
            println(ostdout, "== actual ==\n$result\n")
            false
          end
        end |> all
      finally
        redirect_stdin(ostdin)
        redirect_stdout(ostdout)
      end
    end
    submit() = test() && (program=@__FILE__; run(`echo atcoder-submit $program`))
    !isinteractive() && submit()
  end
end