#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <functional>
#include <map>
#include <iomanip>
#include <math.h> 
#include <stack>
#include <queue>
#include <bitset>
#include <cstdlib>
#include <tuple>
#include <cctype>
#include <ctype.h>
#include <set>
#include <sstream>

using namespace std;


int main() {
	int i, j, k;   
	string s;

	cin >> s;
	int cnt = 0;

	for (i = 0; i < s.length(); i++) {
		if (s[i] == '0') {
			cnt += 10;
		}
		else {
			cnt += (int)s[i] - 48;
		}
	}

	cout << cnt << endl;

	getchar();
	getchar();
	return 0;
}