package main

import (
	"fmt"
	"strconv"
)

func main() {
	var s string
	fmt.Scan(&s)

	ans := 0
	for _, c := range s {
		if c < 'a' || 'z' < c {
			n, _ := strconv.Atoi(string(c))
			ans += n
		}
	}
	fmt.Println(ans)
}