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

int main() {
	string s;
	int ans = 0;
	cin >> s;
	for (int i = 0; i < 9; i++) {
		if (s[i] == '0')ans += 10;
		else ans += s[i] - '0';
	}
	cout << ans << endl;
	fflush (stdin);
	getchar();
	return 0;
}