#include <iostream>

int main() {
    using namespace std;
    int c = 0;
    int s;
    cin >> s;
    for (int i = 0; i < 9; i++) {
        c += s % 10;
        if (s % 10 == 0) {
            c += 10;
        }
        s /= 10;
    }
    cout << c << endl;
}