#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <math.h>
using namespace std;

int main() {
    string s;
    int ans = 0;
    cin >> s;
    for(int i = 0;i < s.length();i++){
        if(s[i] == '0')ans += 10;
        else if(s[i] == '1')ans += 1;
        else if(s[i] == '2')ans += 2;
        else if(s[i] == '3')ans += 3;
        else if(s[i] == '4')ans += 4;
        else if(s[i] == '5')ans += 5;
        else if(s[i] == '6')ans += 6;
        else if(s[i] == '7')ans += 7;
        else if(s[i] == '8')ans += 8;
        else if(s[i] == '9')ans += 9;
    }
    cout << ans;
    return 0;
}