fn main() {
    let s: Vec<char> = {
        let mut line: String = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.trim().chars().collect()
    };

    let mut ans = 0;

    for x in s{
        if '0'<=x && x<='9'{
            ans+=x as i64 - 48;
            //println!("{}",ans);
            //println!("{}",x);
        }
    }

    println!("{}",ans);


}