from math import sqrt

def sol():
  lo = 0.9e-5
  hi = 12.2200001e74
  for _ in range(24):
    me = sqrt(lo * hi)
    print("? {:.100f}".format(me), flush=True)
    res = input()
    if res == "Yes":
      lo = me
    else:
      hi = me
  me = sqrt(lo * hi)
  print("! {:.100f}".format(me), flush=True)


T = int(input())
for _ in range(T):
  sol()