use std::io::stdin;

fn get_line() -> String {
    let mut line = String::new();
    stdin().read_line(&mut line).ok();
    line
}

fn main() {
    let line = get_line();
    let line = line.as_str();

    let mut result = String::new();
    for i in line.chars() {
        if i.is_uppercase() {
            result.push(i.to_ascii_lowercase());
        } else {
            result.push(i.to_ascii_uppercase())
        }
    }
    println!("{}", result);
}