#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(n); i++)

int main() {
    cout.precision(10);
    fixed(cout);
    int T; cin >> T;
    while(T--){
        double l = -6.0 * log(10);
        double r = log(12.2199999) + 74.0 * log(10);
        rep(t,24){
            double m = (l+r) / 2;
            double em = exp(m);
            cout << "? " << em << endl << flush;
            string res; cin >> res;
            if(res == "-1") return 0;
            if(res == "Yes") r = m;
            else l = m;
        }
        double m = (l+r)/2;
        cout << "! " << exp(m) << endl << flush;
    }
    return 0;
}