#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

int main(){
    string S;
    cin >> S;
    int ans = 0;
    for(int i = 0; i < 9; i++){
        if(S[i] == '0'){
            ans += 10;
        }else{
            ans += S[i] - '0';
        }
    }
    cout << ans << endl;
}