fn main() {
    println!("Hello, world!");

    println!("0x{:x}", 0b1111_1010_1111_1010_1111_1010_1111);
    println!("0b{:b}", 0xfafafaf);
    println!("{}", 0xfafafaf);
    println!("{}", 0xfeefee);
    println!("0b{:b}", 0xfeefee);
}