use std::io::BufRead;

fn main() {
    let sum: i64 = std::io::stdin().lock()
        .lines()
        .flat_map(|maybe_line| maybe_line.ok().into_iter()
            .flat_map(|line| line.trim().parse::<i64>().ok()))
        .sum();
    println!("Sum: {}", sum);
}