fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn main() {
    let input: String = read();
    let result: String = input.chars().map(|a| {
        if a.is_uppercase() {
            a.to_ascii_lowercase()
        } else {
            a.to_ascii_uppercase()
        }
    }).collect();
    println!("{}", result);
}