use std::io;
use std::io::BufRead;

fn main() {
    let reader = io::stdin();
    let mut buffer = reader.lock();
    //let writer = io::stdout();

    let mut sum = 0;

    loop {
        let consumed = match buffer.fill_buf() {
            Ok(bytes) if bytes.len() == 0 => break,
            Ok(bytes) => {
                sum += bytes.iter().fold(0, |acc, &item|
                    if item > 48 && item < 58 {
                        acc + item as u32 - 48
                    } else {
                        acc
                    });
                bytes.len()
                },
            Err(_) => panic!()
        };
        buffer.consume(consumed);
    }
    println!("{}", sum);
}