#include <bits/stdc++.h>
using namespace std;

int main() {
	string s;
	cin >> s;
	int ans = 0;
	for (auto &c : s) {
		int score = c - '0';
		if (score == 0) {
			score = 10;
		}
		ans += score;
	}
	cout << ans << endl;
	return 0;
}