import scala.collection.mutable
import scala.collection.mutable.ArrayBuffer
import scala.io.StdIn.*
import scala.math.*
import scala.util.chaining.*


@main def main =
  val testCase = readLine().toInt
  for _ <- 0 until testCase do
    var max = log10(12.22) + 74
    var min = -10.0
    for _ <- 0 until 24 do
      val mid = (min + max) / 2
      val x = pow(10, mid)
      println(f"? $x%.15f")
      val response = readLine().trim
      System.err.println(response)
      val yes = response == "Yes"
      if yes then
        max = mid
      else
        min = mid
    println(f"! ${pow(10, max)}%.15f")