#line 1 "main.cpp"
#include<bits/stdc++.h>
using namespace std;
using lint=long long;

int main(){
    lint t;
    cin>>t;
    auto f=[&](long double x)->bool{
        cout<<"? "<<x<<endl<<flush;
        string s;
        cin>>s;
        return s=="Yes";
    };
    while(t--){
        long double x=1;
        lint cnt=24;
        while(cnt){
            cnt--;
            if(!f(exp(x))){
                x*=2;
            }else{
                break;
            }
        }
        long double l=0,r=x;
        while(cnt){
            cnt--;
            long double m=(l+r)/2;
            if(!f(exp(m)))l=m;
            else r=m;
        }
        cout<<exp((r+l)/2)<<endl;
    }
}