fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let s = s.trim();

    println!(
        "{}",
        match s {
            "A" => "A#",
            "B" => "C",
            "C" => "C#",
            "D" => "D#",
            "E" => "F",
            "F" => "F#",
            "G" => "G#",
            _ => "Error",
        }
    );
}