use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let s = itr.next().unwrap();
    let a = s
        .chars()
        .flat_map(char::to_uppercase)
        .collect::<Vec<char>>();
    let b = s
        .chars()
        .flat_map(char::to_lowercase)
        .collect::<Vec<char>>();
    let s = s.chars().collect::<Vec<char>>();
    for i in 0..s.len() {
        if a[i] != s[i] {
            print!("{}", a[i]);
        } else {
            print!("{}", b[i]);
        }
    }
    println!("",);
}