#![allow(unused)]
fn main() {
    pub fn process<'a, I>(stream: I) -> u64
    where I: Iterator<Item = &'a u64>
    {
        stream.fold(0, |a, n| a + n)
    }

    let list = [1u64, 1000, 200, 3000];
    dbg!(process(list.into_iter()));
    return;
}