fn main() {
    let a = "12345678910111213141516171819";
    let vec1: &str = &a;
    vec1.chars()
        .collect::<Vec<char>>()
        .windows(3)
        .for_each(|window| {
            println!("Window");
            window.iter().for_each(|my_char| {
                println!("hi {:#?}", my_char.to_digit(10));
            });
        });
}