#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;

int main() {
    string s;
    cin >> s;

    int r = 0;
    for (auto& c : s) {
        int t = c - '0';
        if (t == 0) t = 10;
        r += t;
    }

    cout << r << endl;

    return 0;
}