#include<stdio.h>
#include<iostream>
using namespace std;
int main (){
    string s;
    cin >> s;
    int total = 0;
    for(int i=0;  i < s.length(); i++){
        if ( s[i] - '0' == 0) total += 10;
        else total += s[i] - '0';
    }
    cout << total << endl;
    return 0;
}