fn main() {
    let mut line = String::new();
    let _ = std::io::stdin().read_line(&mut line);
    let result: String = line.chars().map(|a| {
        if a.is_uppercase() {
            a.to_ascii_lowercase()
        } else {
            a.to_ascii_uppercase()
        }
    }).collect();
    println!("{}", result);
}