use std::io;

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

    for c in s.trim().chars() {
        if c.is_lowercase() {
            print!("{}", c.to_uppercase());
        } else {
            print!("{}", c.to_lowercase());
        }
    }
    println!("");
}