use std::io::stdin;
pub fn main() {
    let stdin = {
        let mut buf = String::new();
        let _ = stdin().read_line(&mut buf);
        buf
    };
    let answer = stdin
        .chars()
        .map(|x| {
            if x.is_uppercase() {
                x.to_lowercase().to_string()
            } else {
                x.to_uppercase().to_string()
            }
        })
        .collect::<String>();
    println!("{}", answer);
}