import scala.io.StdIn

/**
  * Created by Administrator on 2016/11/25 0025.
  */
object Main extends App {
  def ng(): Unit = {
    println("NG")
  }

  def ok(): Unit = {
    println("OK")
  }

  def leadingZero(str:String):Boolean={
    return (str.charAt(0)=='0'&&str.length>1)
  }

  try {
    var A = StdIn.readLine()
    var B = StdIn.readLine()
    if (leadingZero(A)||leadingZero(B)) {
      throw new Exception("leading zero")
    }
    var (a, b) = (A.toInt, B.toInt)
    if (math.max(a, b) > 12345) {
      throw new Exception("> 12345")
    }
    ok()

  } catch {
    case ex: Exception => {
      Console.err.println(ex)
      ng()
    }
  }


}