#include <iostream>
#include <string>
using namespace std;

int main() {
	constexpr const char one = '1';
	constexpr const char nine = '9';
	string s;
	cin >> s;

	int sum = 0;
	for(const auto& c: s) {
		if(one <= c && c <= nine) {
			sum += c - one + 1;
		}
	}

	cout << sum << endl;

	return 0;
}