use std::io::{stdin, Read, StdinLock};
use std::str::FromStr;

struct Input {
    s: String,
}

fn read_input(cin_lock: &mut StdinLock) -> Input {
    Input {
        s: next_token(cin_lock),
    }
}

fn solve(input: Input) {
    println!(
        "{:?}",
        input
            .s
            .chars()
            .into_iter()
            .filter(|c| c.is_digit(10))
            .map(|c| c.to_digit(10).unwrap())
            .sum::<u32>()
    );
}

fn next_token<T: FromStr>(cin_lock: &mut StdinLock) -> T {
    cin_lock
        .by_ref()
        .bytes()
        .map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>()
        .parse::<T>()
        .ok()
        .unwrap()
}

fn main() {
    let cin = stdin();
    let mut cin_lock = cin.lock();
    let input = read_input(&mut cin_lock);
    solve(input);
}