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
  val maxValue = BigDecimal("1222" + "0" * 72)
  for _ <- 0 until testCase do
    var max = log10(12.22) + 74
    var min = -6.0
    for _ <- 0 until 24 do
      val mid = (min + max) / 2
      val x = f"${pow(10, mid)}%.15f"
      println(s"? ${maxValue.min(BigDecimal(x)).formatted("%.15f")}")
      val response = readLine().trim
      val yes = response == "Yes"
      if yes then
        min = mid
      else
        max = mid
      //println(max - min)
    println(s"! ${maxValue.min(BigDecimal(f"${pow(10, (min + max) / 2)}%.15f")).formatted("%.15f")}")