T = int(input())

for _ in range(T):
    maxlim = 12.22e74
    minlim = 10e-5
    for _ in range(24):
        q = (maxlim+minlim) * 0.5
        print('?',q)
        a = input()
        if a == 'Yes':
            maxlim = q
        elif a == 'No':
            minlim = q
        else:
            exit()
    print('!',(maxlim+minlim) * 0.5)