/* -*- coding: utf-8 -*-
 *
 * 656.cc: No.656 ゴルフ - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int N = 9;

/* typedef */

/* global variables */

/* subroutines */

/* main */

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

  int sum = 0;
  for (int i = 0; i < N; i++)
    sum += (s[i] == '0') ? 10 : (s[i] - '0');

  printf("%d\n", sum);
  return 0;
}