#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define rep(i, a, n) for (int i = a; i < n; ++i)

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

    int ans = 0;
    rep(i, 0, s.length()) {
        int cnt = s[i] - '0';
        if (cnt == 0) ans += 10;
        else ans += cnt;
    }
    cout << ans << endl;
    return 0;
}