T=int(input()) for t in range(T): l=1e-6 r=12.22*1e74 for _ in range(24): mid=(l*r)**.5 print("?",mid) S=input() assert S!="-1" if S=="Yes": l=mid elif S=="No": r=mid else: exit() ans=2*l*r/(l+r) print("!",ans)