use proconio::input_interactive;

#[allow(non_snake_case)]
fn main() {
    input_interactive! {
        a: char,
    }
    for i in 0..26 {
        if i == 0 {
            println!("? {}{}", a, a);
        }
        else {
            input_interactive! {
                (_, S): (char, String),
            }
            let b = S.chars().last().unwrap();
            println!("? {}{}", b, a);
        }
    }
}