package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
)

func solve(in io.Reader, out, err io.Writer) {
	sum, temp := 0, []byte{}
	fmt.Fscan(in, &temp)

	for i := range temp {
		if temp[i] <= '9' && '0' <= temp[i] {
			sum += int(temp[i] - '0')
		}
	}

	fmt.Fprintln(out, sum)

}

func main() {
	br := bufio.NewReaderSize(os.Stdin, int(1e4))
	solve(br, os.Stdout, os.Stderr)
}