fn read() -> String {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    String::from(s.trim())
}

fn main() {
    let u = 12.22f64 * 10f64.powi(74);
    let mut p = vec![];
    let mut x = 0f64;
    while x < u {
        p.push(x);
        x = (x + 0.00001).max(x * 1.00001);
    }
    let t = read().parse::<u32>().unwrap();
    for _ in 0..t {
        let mut l = 0;
        let mut r = p.len() - 1;
        for _ in 0..24 {
            if l >= r {
                break;
            }
            let m = (l + r) / 2;
            println!("? {}", p[m]);
            let ans = read();
            if ans == "Yes" {
                l = m;
            } else {
                r = m;
            }
        }
        println!("! {}", (p[l] + p[r]) * 0.5);
    }
}