use rand::Rng;
fn main() {
let mut rng = rand::thread_rng();
let random_number: u128 = rng.gen_range(10000000000000000000..99999999999999999999);
println!("Random 20-digit number: {}", random_number);
}
/*
run:
Random 20-digit number: 68222901072957437989
*/