#include <iostream>
#include <string>

int main(){
  constexpr const char one = '1';
  constexpr const char nine = '9';
  std::string S;
  std::cin >> S;
  
  int sum = 0;
  for(const auto& c : S){
    if(one <= c && c <= nine){
      sum += c - one + 1;
    }
  }
  std::cout << sum << std::endl;
  
  return 0;
}