#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>

using namespace std;

int m(char c) {
    int t = c - '0';
    if (t == 0) {
        return 10;
    } else {
        return t;
    }
}

int main() {


    string S;
    cin >> S;
    int sum = 0;
    for (int i = 0; i < S.size(); ++i) {
        sum += m(S[i]);
    }

    cout << sum << endl;
    return 0;
}