use std::io::*;
use std::str::*;

fn read<T: FromStr>(sl: &mut StdinLock) -> Option<T> {
    let s = sl.by_ref().bytes().map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();

    s.parse::<T>().ok()
}

fn run(sl: &mut StdinLock) {
    let s = read::<String>(sl).unwrap();
    println!("{}", s.chars().map(|c| {
        if c.is_uppercase() {
            c.to_ascii_lowercase()
        }
        else {
            c.to_ascii_uppercase()
        }
    }).collect::<String>());
}

fn main() {
    let s = stdin();
    let mut sl = s.lock();
    run(&mut sl);
}