#include <bits/stdc++.h>
#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

void solve() {
  int ans=0;
  string s;
  cin >> s;
  const vector<int> v{10, 1, 2, 3, 4, 5, 6, 7, 8, 9};
  rep(i, 0, 9) ans += v[s[i] - '0'];
  cout << ans << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  getchar();
}