/**
 *  author:   TakeruOkuyama
 *  created:  2020-04-09 14:53:46
**/
#include <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;

const int MOD = 1000000007;

int main(){
    string S;
    cin >> S;
    int ans = 0;
    rep(i, S.size()){
        if(S[i] == '0'){
            ans += 10;
        }else{
            ans += int(S[i]-'0');
        }
    }
    cout << ans << endl;
return 0;}

/**
 * g++ code.cpp
 * ./a.out
 * shift + ctrl + i
**/