#include<iostream>
#include<string>
using namespace std;
int main() {
	char S[10];
	int sum = 0;
	cin >> S;
	for (int i = 0; i < 9; i++) {
		if (S[i] == '0') sum += 10;
		else sum += (int)S[i] - 48;
	}
	cout << sum << endl;
	return 0;
}