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()