for _ in range(int(input())):
    r = 12.22 * 10 ** 74
    l = 10 ** -6
    for _ in range(24):
        mid = (l * r) ** 0.5
        print("?", mid, flush=True)
        if input() == "Yes":
            r = mid
        else:
            l = mid

    print("!", (l * r) ** 0.5, flush=True)