#include <bits/stdc++.h>
#define REP(i, a, n) for(ll i = ((ll) a); i < ((ll) n); i++)
using namespace std;
typedef long long ll;

int main(void) {
  string S;
  cin >> S;

  ll ans = 0;
  REP(i, 0, S.length()) {
    ll x = S[i] - '0';
    if(x == 0) ans += 10;
    else ans += x;
  }
  cout << ans << endl;
}