#include<iostream>
#include<string>
#include<vector>
using namespace std;
int main() {
	char s[10];
	cin >> s;
	int ans = 0;
	for (int i = 0; i < 9; i++) {
		if (s[i] == '0')
			ans += 10;
		else
			ans += s[i] - '0';
	}

	cout << ans << endl;
	return 0;
}